From 1109132f09d75da9a28b649c7677bb6ce07c40c0 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:41:45 -0500 Subject: initial commit --- .../reference/global_objects/array/from/index.html | 243 +++++++++++ .../global_objects/array/includes/index.html | 169 +++++++ .../reference/global_objects/array/index.html | 485 +++++++++++++++++++++ .../global_objects/array/unshift/index.html | 94 ++++ .../javascript/reference/global_objects/index.html | 183 ++++++++ .../global_objects/object/assign/index.html | 272 ++++++++++++ .../reference/global_objects/object/index.html | 184 ++++++++ .../reference/global_objects/promise/index.html | 244 +++++++++++ .../reference/global_objects/string/index.html | 314 +++++++++++++ 9 files changed, 2188 insertions(+) create mode 100644 files/he/web/javascript/reference/global_objects/array/from/index.html create mode 100644 files/he/web/javascript/reference/global_objects/array/includes/index.html create mode 100644 files/he/web/javascript/reference/global_objects/array/index.html create mode 100644 files/he/web/javascript/reference/global_objects/array/unshift/index.html create mode 100644 files/he/web/javascript/reference/global_objects/index.html create mode 100644 files/he/web/javascript/reference/global_objects/object/assign/index.html create mode 100644 files/he/web/javascript/reference/global_objects/object/index.html create mode 100644 files/he/web/javascript/reference/global_objects/promise/index.html create mode 100644 files/he/web/javascript/reference/global_objects/string/index.html (limited to 'files/he/web/javascript/reference/global_objects') diff --git a/files/he/web/javascript/reference/global_objects/array/from/index.html b/files/he/web/javascript/reference/global_objects/array/from/index.html new file mode 100644 index 0000000000..1ab52ffa12 --- /dev/null +++ b/files/he/web/javascript/reference/global_objects/array/from/index.html @@ -0,0 +1,243 @@ +--- +title: ()Array.from +slug: Web/JavaScript/Reference/Global_Objects/Array/from +translation_of: Web/JavaScript/Reference/Global_Objects/Array/from +--- +
מתודת ה-
+ +
Array.from() 
+ +
יוצרת מערך חדש שהוא העתק בעומק אחד (לא יכלול את האובייקטים אליהם יש הפניות מאיברים במערך הנתון) של המערך או אובייקט איטרבילי המועבר כפרמטר.
+ +
+ +
{{EmbedInteractiveExample("pages/js/array-from.html")}}
+ + + +

Syntax

+ +
Array.from(arrayLike[, mapFn[, thisArg]])
+
+ +

Parameters

+ +
+
arrayLike
+
An array-like or iterable object to convert to an array.
+
mapFn {{Optional_inline}}
+
Map function to call on every element of the array.
+
thisArg {{Optional_inline}}
+
Value to use as this when executing mapFn.
+
+ +

Return value

+ +

A new {{jsxref("Array")}} instance.

+ +

Description

+ +

Array.from() lets you create Arrays from:

+ + + +

Array.from() has an optional parameter mapFn, which allows you to execute a {{jsxref("Array.prototype.map", "map")}} function on each element of the array (or subclass object) that is being created. More clearly, Array.from(obj, mapFn, thisArg) has the same result as Array.from(obj).map(mapFn, thisArg), except that it does not create an intermediate array. This is especially important for certain array subclasses, like typed arrays, since the intermediate array would necessarily have values truncated to fit into the appropriate type.

+ +

The length property of the from() method is 1.

+ +

In ES2015, the class syntax allows for sub-classing of both built-in and user defined classes; as a result, static methods such as Array.from are "inherited" by subclasses of Array and create new instances of the subclass, not Array.

+ +

Examples

+ +

Array from a String

+ +
Array.from('foo');
+// [ "f", "o", "o" ]
+ +

Array from a Set

+ +
const set = new Set(['foo', 'bar', 'baz', 'foo']);
+Array.from(set);
+// [ "foo", "bar", "baz" ]
+ +

Array from a Map

+ +
const map = new Map([[1, 2], [2, 4], [4, 8]]);
+Array.from(map);
+// [[1, 2], [2, 4], [4, 8]]
+
+const mapper = new Map([['1', 'a'], ['2', 'b']]);
+Array.from(mapper.values());
+// ['a', 'b'];
+
+Array.from(mapper.keys());
+// ['1', '2'];
+
+ +

Array from an Array-like object (arguments)

+ +
function f() {
+  return Array.from(arguments);
+}
+
+f(1, 2, 3);
+
+// [ 1, 2, 3 ]
+ +

Using arrow functions and Array.from

+ +
// Using an arrow function as the map function to
+// manipulate the elements
+Array.from([1, 2, 3], x => x + x);
+// [2, 4, 6]
+
+
+// Generate a sequence of numbers
+// Since the array is initialized with `undefined` on each position,
+// the value of `v` below will be `undefined`
+Array.from({length: 5}, (v, i) => i);
+// [0, 1, 2, 3, 4]
+
+ +

Sequence generator (range)

+ +
// Sequence generator function (commonly referred to as "range", e.g. Clojure, PHP etc)
+const range = (start, stop, step) => Array.from({ length: (stop - start) / step + 1}, (_, i) => start + (i * step));
+
+// Generate numbers range 0..4
+range(0, 4, 1);
+// [0, 1, 2, 3, 4]
+
+// Generate numbers range 1..10 with step of 2
+range(1, 10, 2);
+// [1, 3, 5, 7, 9]
+
+// Generate the alphabet using Array.from making use of it being ordered as a sequence
+range('A'.charCodeAt(0), 'Z'.charCodeAt(0), 1).map(x => String.fromCharCode(x));
+// ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"]
+
+ +

Polyfill

+ +

Array.from was added to the ECMA-262 standard in the 6th edition (ES2015); as such it may not be present in other implementations of the standard. You can work around this by inserting the following code at the beginning of your scripts, allowing use of Array.from in implementations that don't natively support it. This algorithm is exactly the one specified in ECMA-262, 6th edition, assuming Object and TypeError have their original values and that callback.call evaluates to the original value of {{jsxref("Function.prototype.call")}}. In addition, since true iterables can not be polyfilled, this implementation does not support generic iterables as defined in the 6th edition of ECMA-262.

+ +
// Production steps of ECMA-262, Edition 6, 22.1.2.1
+if (!Array.from) {
+  Array.from = (function () {
+    var toStr = Object.prototype.toString;
+    var isCallable = function (fn) {
+      return typeof fn === 'function' || toStr.call(fn) === '[object Function]';
+    };
+    var toInteger = function (value) {
+      var number = Number(value);
+      if (isNaN(number)) { return 0; }
+      if (number === 0 || !isFinite(number)) { return number; }
+      return (number > 0 ? 1 : -1) * Math.floor(Math.abs(number));
+    };
+    var maxSafeInteger = Math.pow(2, 53) - 1;
+    var toLength = function (value) {
+      var len = toInteger(value);
+      return Math.min(Math.max(len, 0), maxSafeInteger);
+    };
+
+    // The length property of the from method is 1.
+    return function from(arrayLike/*, mapFn, thisArg */) {
+      // 1. Let C be the this value.
+      var C = this;
+
+      // 2. Let items be ToObject(arrayLike).
+      var items = Object(arrayLike);
+
+      // 3. ReturnIfAbrupt(items).
+      if (arrayLike == null) {
+        throw new TypeError('Array.from requires an array-like object - not null or undefined');
+      }
+
+      // 4. If mapfn is undefined, then let mapping be false.
+      var mapFn = arguments.length > 1 ? arguments[1] : void undefined;
+      var T;
+      if (typeof mapFn !== 'undefined') {
+        // 5. else
+        // 5. a If IsCallable(mapfn) is false, throw a TypeError exception.
+        if (!isCallable(mapFn)) {
+          throw new TypeError('Array.from: when provided, the second argument must be a function');
+        }
+
+        // 5. b. If thisArg was supplied, let T be thisArg; else let T be undefined.
+        if (arguments.length > 2) {
+          T = arguments[2];
+        }
+      }
+
+      // 10. Let lenValue be Get(items, "length").
+      // 11. Let len be ToLength(lenValue).
+      var len = toLength(items.length);
+
+      // 13. If IsConstructor(C) is true, then
+      // 13. a. Let A be the result of calling the [[Construct]] internal method
+      // of C with an argument list containing the single item len.
+      // 14. a. Else, Let A be ArrayCreate(len).
+      var A = isCallable(C) ? Object(new C(len)) : new Array(len);
+
+      // 16. Let k be 0.
+      var k = 0;
+      // 17. Repeat, while k < len… (also steps a - h)
+      var kValue;
+      while (k < len) {
+        kValue = items[k];
+        if (mapFn) {
+          A[k] = typeof T === 'undefined' ? mapFn(kValue, k) : mapFn.call(T, kValue, k);
+        } else {
+          A[k] = kValue;
+        }
+        k += 1;
+      }
+      // 18. Let putStatus be Put(A, "length", len, true).
+      A.length = len;
+      // 20. Return A.
+      return A;
+    };
+  }());
+}
+
+ +

Specifications

+ + + + + + + + + + + + + + + + + + + + + +
SpecificationStatusComment
{{SpecName('ESDraft', '#sec-array.from', 'Array.from')}}{{Spec2('ESDraft')}}
{{SpecName('ES2015', '#sec-array.from', 'Array.from')}}{{Spec2('ES2015')}}Initial definition.
+ +

Browser compatibility

+ + + +

{{Compat("javascript.builtins.Array.from")}}

+ +

See also

+ + diff --git a/files/he/web/javascript/reference/global_objects/array/includes/index.html b/files/he/web/javascript/reference/global_objects/array/includes/index.html new file mode 100644 index 0000000000..0cc6181f0d --- /dev/null +++ b/files/he/web/javascript/reference/global_objects/array/includes/index.html @@ -0,0 +1,169 @@ +--- +title: Array.prototype.includes() +slug: Web/JavaScript/Reference/Global_Objects/Array/includes +tags: + - ג'אווה סקריפט + - מערך + - פוליפיל + - פרוטוטייפ +translation_of: Web/JavaScript/Reference/Global_Objects/Array/includes +--- +
{{JSRef}}
+ +
שיטת includes() קובעת אם מערך מכיל אלמנט מסויים, מחזיר true או false בהתאם.
+ +
 
+ +

תחביר

+ +
var boolean = array.includes(searchElement[, fromIndex])
+ +

פרמטרים

+ +
+
searchElement
+
האלמנט אותו מחפשים
+
fromIndex
+
אופציונלי. המיקום במערך בו להתחיל את החיפוש אחר searchElement. ערך שלילי יתחיל את החיפוש מהערך האחרון (array.length) + fromIndex בסדר עולה. ברירת מחדל 0.
+
+ +

ערך מוחזר (Return)

+ +

{{jsxref("Boolean")}}.

+ +

דוגמאות

+ +
[1, 2, 3].includes(2);     // true
+[1, 2, 3].includes(4);     // false
+[1, 2, 3].includes(3, 3);  // false
+[1, 2, 3].includes(3, -1); // true
+[1, 2, NaN].includes(NaN); // true
+
+ +

פוליפיל - Polyfill

+ +
if (!Array.prototype.includes) {
+  Array.prototype.includes = function(searchElement /*, fromIndex*/) {
+    'use strict';
+    if (this == null) {
+      throw new TypeError('Array.prototype.includes called on null or undefined');
+    }
+
+    var O = Object(this);
+    var len = parseInt(O.length, 10) || 0;
+    if (len === 0) {
+      return false;
+    }
+    var n = parseInt(arguments[1], 10) || 0;
+    var k;
+    if (n >= 0) {
+      k = n;
+    } else {
+      k = len + n;
+      if (k < 0) {k = 0;}
+    }
+    var currentElement;
+    while (k < len) {
+      currentElement = O[k];
+      if (searchElement === currentElement ||
+         (searchElement !== searchElement && currentElement !== currentElement)) { // NaN !== NaN
+        return true;
+      }
+      k++;
+    }
+    return false;
+  };
+}
+
+ +

מפרט

+ + + + + + + + + + + + + + + + + + + +
  מפרטסטטוסהערה
{{SpecName('ES7', '#sec-array.prototype.includes', 'Array.prototype.includes')}}{{Spec2('ES7')}}הגדרה ראשונית
{{SpecName('ESDraft', '#sec-array.prototype.includes', 'Array.prototype.includes')}}{{Spec2('ESDraft')}} 
+ +

תאימות דפדפנים

+ +
{{CompatibilityTable}}
+ +
+ + + + + + + + + + + + + + + + + + + + + +
מאפייןChromeFirefox (Gecko)Internet ExplorerEdgeOperaSafari
תמיכה בסיסית +

{{CompatChrome(47)}}

+ 		43{{CompatNo}}14279+349
+
+ +
+ + + + + + + + + + + + + + + + + + + + + + + +
מאפייןAndroidAndroid WebviewFirefox Mobile (Gecko)IE MobileOpera MobileSafari MobileChrome for Android
תמיכה בסיסית{{CompatNo}} +

{{CompatChrome(47)}}

+ 		43{{CompatNo}}349 +

{{CompatChrome(47)}}

+
+
+ +

ראה עוד

+ + diff --git a/files/he/web/javascript/reference/global_objects/array/index.html b/files/he/web/javascript/reference/global_objects/array/index.html new file mode 100644 index 0000000000..4dac733b4a --- /dev/null +++ b/files/he/web/javascript/reference/global_objects/array/index.html @@ -0,0 +1,485 @@ +--- +title: Array +slug: Web/JavaScript/Reference/Global_Objects/Array +tags: + - Global Objects + - JavaScript + - NeedsTranslation + - Reference + - TopicStub + - דוגמא + - מערך +translation_of: Web/JavaScript/Reference/Global_Objects/Array +--- +

האובייקט מערך(Array) בג'אווה סקריפט הוא אובייקט גלובלי אשר משמש לבניית מערכים שהם אובייקטים דמויי רשימה .

+ +

צור מערך

+ +
var fruits = ["Apple", "Banana"];
+
+console.log(fruits.length);
+// 2
+
+ +

קבל גישה לאיבר(ע"י האינדקס שלו) במערך

+ +
var first = fruits[0];
+// Apple
+
+var last = fruits[fruits.length - 1];
+// Banana
+
+ +

השתמש בלולאה על המערך 

+ +
fruits.forEach(function (item, index, array) {
+  console.log(item, index);
+});
+// Apple 0
+// Banana 1
+
+ +

הוסף איבר לסוף המערך

+ +
var newLength = fruits.push("Orange");
+// ["Apple", "Banana", "Orange"]
+
+ +

הסר את האיבר האחרון במערך

+ +
var last = fruits.pop(); // remove Orange (from the end)
+// ["Apple", "Banana"];
+
+ +

הסר איבר הראשון מערך

+ +
var first = fruits.shift(); // remove Apple from the front
+// ["Banana"];
+
+ +

הוסף איבר לראשית המערך

+ +
var newLength = fruits.unshift("Strawberry") // add to the front
+// ["Strawberry", "Banana"];
+
+ +

מצא את האינדקס של איבר במערך

+ +
fruits.push("Mango");
+// ["Strawberry", "Banana", "Mango"]
+
+var pos = fruits.indexOf("Banana");
+// 1
+
+ +

הסר איבר על ידי האינדקס(מיקום) שלו

+ +
var removedItem = fruits.splice(pos, 1); // this is how to remove an item
+// ["Strawberry", "Mango"]
+
+ +

צור עותק של המערך

+ +
var shallowCopy = fruits.slice(); // this is how to make a copy
+// ["Strawberry", "Mango"]
+
+ +

תחביר

+ +
[element0, element1, ..., elementN]
+new Array(element0, element1[, ...[, elementN]])
+new Array(arrayLength)
+ +

פרמטרים

+ +
+
elementN
+
A JavaScript array is initialized with the given elements, except in the case where a single argument is passed to the Array constructor and that argument is a number (see the arrayLength parameter below).Note that this special case only applies to JavaScript arrays created with the Array constructor, not array literals created with the bracket syntax.
+
arrayLength
+
If the only argument passed to the Array constructor is an integer between 0 and 232-1 (inclusive), this returns a new JavaScript array with length set to that number. If the argument is any other number, a {{jsxref("RangeError")}} exception is thrown.
+
+ +

Description

+ +

Arrays are list-like objects whose prototype has methods to perform traversal and mutation operations. Neither the length of a JavaScript array nor the types of its elements are fixed. Since an array's length can change at any time, and data can be stored at non-contiguous locations in the array, JavaScript arrays are not guaranteed to be dense; this depends on how the programmer chooses to use them. In general, these are convenient characteristics; but if these features are not desirable for your particular use, you might consider using typed arrays.

+ +

Some people think that you shouldn't use an array as an associative array. In any case, you can use plain {{jsxref("Global_Objects/Object", "objects")}} instead, although doing so comes with its own caveats. See the post Lightweight JavaScript dictionaries with arbitrary keys as an example.

+ +

גישה לאלמנטים שבמערך

+ +

מערכים ב - JavaScript מסודרים לפי מספרים מאפס ומעלה: מספרו של האיבר הראשון במערך הוא 0 ומספרו של האיבר האחרון במערך שווה לכמות האיברים במערך (אורכו של המערך - Array.length) פחות 1.

+ +
var arr = ['this is the first element', 'this is the second element'];
+console.log(arr[0]);              // logs 'this is the first element'
+console.log(arr[1]);              // logs 'this is the second element'
+console.log(arr[arr.length - 1]); // logs 'this is the second element'
+
+ +

Array elements are object properties in the same way that toString is a property, but trying to access an element of an array as follows throws a syntax error, because the property name is not valid:

+ +
console.log(arr.0); // a syntax error
+
+ +

There is nothing special about JavaScript arrays and the properties that cause this. JavaScript properties that begin with a digit cannot be referenced with dot notation; and must be accessed using bracket notation. For example, if you had an object with a property named '3d', it can only be referenced using bracket notation. E.g.:

+ +
var years = [1950, 1960, 1970, 1980, 1990, 2000, 2010];
+console.log(years.0);   // a syntax error
+console.log(years[0]);  // works properly
+
+ +
renderer.3d.setTexture(model, 'character.png');     // a syntax error
+renderer['3d'].setTexture(model, 'character.png');  // works properly
+
+ +

Note that in the 3d example, '3d' had to be quoted. It's possible to quote the JavaScript array indexes as well (e.g., years['2'] instead of years[2]), although it's not necessary. The 2 in years[2] is coerced into a string by the JavaScript engine through an implicit toString conversion. It is for this reason that '2' and '02' would refer to two different slots on the years object and the following example could be true:

+ +
console.log(years['2'] != years['02']);
+
+ +

Similarly, object properties which happen to be reserved words(!) can only be accessed as string literals in bracket notation(but it can be accessed by dot notation in firefox 40.0a2 at least):

+ +
var promise = {
+  'var'  : 'text',
+  'array': [1, 2, 3, 4]
+};
+
+console.log(promise['array']);
+
+ +

Relationship between length and numerical properties

+ +

A JavaScript array's {{jsxref("Array.length", "length")}} property and numerical properties are connected. Several of the built-in array methods (e.g., {{jsxref("Array.join", "join")}}, {{jsxref("Array.slice", "slice")}}, {{jsxref("Array.indexOf", "indexOf")}}, etc.) take into account the value of an array's {{jsxref("Array.length", "length")}} property when they're called. Other methods (e.g., {{jsxref("Array.push", "push")}}, {{jsxref("Array.splice", "splice")}}, etc.) also result in updates to an array's {{jsxref("Array.length", "length")}} property.

+ +
var fruits = [];
+fruits.push('banana', 'apple', 'peach');
+
+console.log(fruits.length); // 3
+
+ +

When setting a property on a JavaScript array when the property is a valid array index and that index is outside the current bounds of the array, the engine will update the array's {{jsxref("Array.length", "length")}} property accordingly:

+ +
fruits[5] = 'mango';
+console.log(fruits[5]); // 'mango'
+console.log(Object.keys(fruits));  // ['0', '1', '2', '5']
+console.log(fruits.length); // 6
+
+ +

Increasing the {{jsxref("Array.length", "length")}}.

+ +
fruits.length = 10;
+console.log(Object.keys(fruits)); // ['0', '1', '2', '5']
+console.log(fruits.length); // 10
+
+ +

Decreasing the {{jsxref("Array.length", "length")}} property does, however, delete elements.

+ +
fruits.length = 2;
+console.log(Object.keys(fruits)); // ['0', '1']
+console.log(fruits.length); // 2
+
+ +

This is explained further on the {{jsxref("Array.length")}} page.

+ +

Creating an array using the result of a match

+ +

The result of a match between a regular expression and a string can create a JavaScript array. This array has properties and elements which provide information about the match. Such an array is returned by {{jsxref("RegExp.exec")}}, {{jsxref("String.match")}}, and {{jsxref("String.replace")}}. To help explain these properties and elements, look at the following example and then refer to the table below:

+ +
// Match one d followed by one or more b's followed by one d
+// Remember matched b's and the following d
+// Ignore case
+
+var myRe = /d(b+)(d)/i;
+var myArray = myRe.exec('cdbBdbsbz');
+
+ +

The properties and elements returned from this match are as follows:

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Property/ElementDescriptionExample
inputA read-only property that reflects the original string against which the regular expression was matched.cdbBdbsbz
indexA read-only property that is the zero-based index of the match in the string.1
[0]A read-only element that specifies the last matched characters.dbBd
[1], ...[n]Read-only elements that specify the parenthesized substring matches, if included in the regular expression. The number of possible parenthesized substrings is unlimited.[1]: bB
+ [2]: d
+ +

Properties

+ +
+
Array.length
+
The Array constructor's length property whose value is 1.
+
{{jsxref("Array.@@species", "get Array[@@species]")}}
+
The constructor function that is used to create derived objects.
+
{{jsxref("Array.prototype")}}
+
Allows the addition of properties to all array objects.
+
+ +

Methods

+ +
+
{{jsxref("Array.from()")}}
+
Creates a new Array instance from an array-like or iterable object.
+
{{jsxref("Array.isArray()")}}
+
Returns true if a variable is an array, if not false.
+
{{jsxref("Array.of()")}}
+
Creates a new Array instance with a variable number of arguments, regardless of number or type of the arguments.
+
+ +

Array instances

+ +

All Array instances inherit from {{jsxref("Array.prototype")}}. The prototype object of the Array constructor can be modified to affect all Array instances.

+ +

Properties

+ +
{{page('/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/prototype', 'Properties')}}
+ +

Methods

+ +

Mutator methods

+ +
{{page('en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/prototype', 'Mutator_methods')}}
+ +

Accessor methods

+ +
{{page('en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/prototype', 'Accessor_methods')}}
+ +

Iteration methods

+ +
{{page('en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/prototype', 'Iteration_methods')}}
+ +

Array generic methods

+ +
+

Array generics are non-standard, deprecated and will get removed near future. Note that you can not rely on them cross-browser. However, there is a shim available on GitHub.

+
+ +

Sometimes you would like to apply array methods to strings or other array-like objects (such as function {{jsxref("Functions/arguments", "arguments", "", 1)}}). By doing this, you treat a string as an array of characters (or otherwise treat a non-array as an array). For example, in order to check that every character in the variable str is a letter, you would write:

+ +
function isLetter(character) {
+  return character >= 'a' && character <= 'z';
+}
+
+if (Array.prototype.every.call(str, isLetter)) {
+  console.log("The string '" + str + "' contains only letters!");
+}
+
+ +

This notation is rather wasteful and JavaScript 1.6 introduced a generic shorthand:

+ +
if (Array.every(str, isLetter)) {
+  console.log("The string '" + str + "' contains only letters!");
+}
+
+ +

{{jsxref("Global_Objects/String", "Generics", "#String_generic_methods", 1)}} are also available on {{jsxref("String")}}.

+ +

These are not part of ECMAScript standards (though the ES2015 {{jsxref("Array.from()")}} can be used to achieve this). The following is a shim to allow its use in all browsers:

+ +
// Assumes Array extras already present (one may use polyfills for these as well)
+(function() {
+  'use strict';
+
+  var i,
+    // We could also build the array of methods with the following, but the
+    //   getOwnPropertyNames() method is non-shimable:
+    // Object.getOwnPropertyNames(Array).filter(function(methodName) {
+    //   return typeof Array[methodName] === 'function'
+    // });
+    methods = [
+      'join', 'reverse', 'sort', 'push', 'pop', 'shift', 'unshift',
+      'splice', 'concat', 'slice', 'indexOf', 'lastIndexOf',
+      'forEach', 'map', 'reduce', 'reduceRight', 'filter',
+      'some', 'every', 'find', 'findIndex', 'entries', 'keys',
+      'values', 'copyWithin', 'includes'
+    ],
+    methodCount = methods.length,
+    assignArrayGeneric = function(methodName) {
+      if (!Array[methodName]) {
+        var method = Array.prototype[methodName];
+        if (typeof method === 'function') {
+          Array[methodName] = function() {
+            return method.call.apply(method, arguments);
+          };
+        }
+      }
+    };
+
+  for (i = 0; i < methodCount; i++) {
+    assignArrayGeneric(methods[i]);
+  }
+}());
+
+ +

דוגמאות

+ +

Creating an array

+ +

The following example creates an array, msgArray, with a length of 0, then assigns values to msgArray[0] and msgArray[99], changing the length of the array to 100.

+ +
var msgArray = [];
+msgArray[0] = 'Hello';
+msgArray[99] = 'world';
+
+if (msgArray.length === 100) {
+  console.log('The length is 100.');
+}
+
+ +

Creating a two-dimensional array

+ +

The following creates a chess board as a two dimensional array of strings. The first move is made by copying the 'p' in (6,4) to (4,4). The old position (6,4) is made blank.

+ +
var board = [
+  ['R','N','B','Q','K','B','N','R'],
+  ['P','P','P','P','P','P','P','P'],
+  [' ',' ',' ',' ',' ',' ',' ',' '],
+  [' ',' ',' ',' ',' ',' ',' ',' '],
+  [' ',' ',' ',' ',' ',' ',' ',' '],
+  [' ',' ',' ',' ',' ',' ',' ',' '],
+  ['p','p','p','p','p','p','p','p'],
+  ['r','n','b','q','k','b','n','r'] ];
+
+console.log(board.join('\n') + '\n\n');
+
+// Move King's Pawn forward 2
+board[4][4] = board[6][4];
+board[6][4] = ' ';
+console.log(board.join('\n'));
+
+ +

Here is the output:

+ +
R,N,B,Q,K,B,N,R
+P,P,P,P,P,P,P,P
+ , , , , , , ,
+ , , , , , , ,
+ , , , , , , ,
+ , , , , , , ,
+p,p,p,p,p,p,p,p
+r,n,b,q,k,b,n,r
+
+R,N,B,Q,K,B,N,R
+P,P,P,P,P,P,P,P
+ , , , , , , ,
+ , , , , , , ,
+ , , , ,p, , ,
+ , , , , , , ,
+p,p,p,p, ,p,p,p
+r,n,b,q,k,b,n,r
+
+ +

Specifications

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
SpecificationStatusComment
{{SpecName('ES1')}}{{Spec2('ES1')}}Initial definition.
{{SpecName('ES5.1', '#sec-15.4', 'Array')}}{{Spec2('ES5.1')}}New methods added: {{jsxref("Array.isArray")}}, {{jsxref("Array.prototype.indexOf", "indexOf")}}, {{jsxref("Array.prototype.lastIndexOf", "lastIndexOf")}}, {{jsxref("Array.prototype.every", "every")}}, {{jsxref("Array.prototype.some", "some")}}, {{jsxref("Array.prototype.forEach", "forEach")}}, {{jsxref("Array.prototype.map", "map")}}, {{jsxref("Array.prototype.filter", "filter")}}, {{jsxref("Array.prototype.reduce", "reduce")}}, {{jsxref("Array.prototype.reduceRight", "reduceRight")}}
{{SpecName('ES2015', '#sec-array-objects', 'Array')}}{{Spec2('ES2015')}}New methods added: {{jsxref("Array.from")}}, {{jsxref("Array.of")}}, {{jsxref("Array.prototype.find", "find")}}, {{jsxref("Array.prototype.findIndex", "findIndex")}}, {{jsxref("Array.prototype.fill", "fill")}}, {{jsxref("Array.prototype.copyWithin", "copyWithin")}}
{{SpecName('ESDraft', '#sec-array-objects', 'Array')}}{{Spec2('ESDraft')}}New method added: {{jsxref("Array.prototype.includes()")}}
+ +

Browser compatibility

+ +
{{CompatibilityTable}}
+ +
+ + + + + + + + + + + + + + + + + + + +
FeatureChromeFirefox (Gecko)Internet ExplorerOperaSafari
Basic support{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}
+
+ +
+ + + + + + + + + + + + + + + + + + + + + +
FeatureAndroidChrome for AndroidFirefox Mobile (Gecko)IE MobileOpera MobileSafari Mobile
Basic support{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}
+
+ +

ראה גם

+ + diff --git a/files/he/web/javascript/reference/global_objects/array/unshift/index.html b/files/he/web/javascript/reference/global_objects/array/unshift/index.html new file mode 100644 index 0000000000..9febfb5ad4 --- /dev/null +++ b/files/he/web/javascript/reference/global_objects/array/unshift/index.html @@ -0,0 +1,94 @@ +--- +title: Array.prototype.unshift() +slug: Web/JavaScript/Reference/Global_Objects/Array/unshift +translation_of: Web/JavaScript/Reference/Global_Objects/Array/unshift +--- +
{{JSRef}}
+ +
המתודה ()unshift  מוסיפה אלמנט אחד או יותר לתחילת מערך ומחזירה את גודלו החדש של המערך. 
+ +
{{EmbedInteractiveExample("pages/js/array-unshift.html")}}
+ +

Syntax

+ +
arr.unshift(element1[, ...[, elementN]])
+ +

פרמטרים

+ +
+
elementN
+
אלמנטים להוספה לתחילת המערך.
+
+ +

ערך מוחזר

+ +

את ערך השדה {{jsxref("Array.length", "length")}} החדש של המערך עליו הופעלה המתודה.

+ +

תאור

+ +

המתודה unshift מכניסה את ערכי האלמנטים שקיבלה כפרמטר לתחילת אובייקט המערך. 

+ +

unshift is intentionally generic; this method can be {{jsxref("Function.call", "called", "", 1)}} or {{jsxref("Function.apply", "applied", "", 1)}} to objects resembling arrays. Objects which do not contain a length property reflecting the last in a series of consecutive, zero-based numerical properties may not behave in any meaningful manner.

+ +

Examples

+ +
var arr = [1, 2];
+
+arr.unshift(0); // result of call is 3, the new array length
+// arr is [0, 1, 2]
+
+arr.unshift(-2, -1); // = 5
+// arr is [-2, -1, 0, 1, 2]
+
+arr.unshift([-3]);
+// arr is [[-3], -2, -1, 0, 1, 2]
+
+ +

Specifications

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
SpecificationStatusComment
{{SpecName('ES3')}}{{Spec2('ES3')}}Initial definition. Implemented in JavaScript 1.2.
{{SpecName('ES5.1', '#sec-15.4.4.13', 'Array.prototype.unshift')}}{{Spec2('ES5.1')}} 
{{SpecName('ES6', '#sec-array.prototype.unshift', 'Array.prototype.unshift')}}{{Spec2('ES6')}} 
{{SpecName('ESDraft', '#sec-array.prototype.unshift', 'Array.prototype.unshift')}}{{Spec2('ESDraft')}} 
+ +

Browser compatibility

+ +
+ + +

{{Compat("javascript.builtins.Array.unshift")}}

+
+ +

See also

+ + diff --git a/files/he/web/javascript/reference/global_objects/index.html b/files/he/web/javascript/reference/global_objects/index.html new file mode 100644 index 0000000000..f215b83a20 --- /dev/null +++ b/files/he/web/javascript/reference/global_objects/index.html @@ -0,0 +1,183 @@ +--- +title: Standard built-in objects +slug: Web/JavaScript/Reference/Global_Objects +tags: + - JavaScript + - Objects + - אובייקטים + - סקריפט + - פונקציות +translation_of: Web/JavaScript/Reference/Global_Objects +--- +
{{jsSidebar("Objects")}}
+ +

This chapter documents all of JavaScript's standard, built-in objects, including their methods and properties.

+ +
+

The term "global objects" (or standard built-in objects) here is not to be confused with the global object. Here, global objects refer to objects in the global scope (but only if ECMAScript 5 strict mode is not used; in that case it returns {{jsxref("undefined")}}). The global object itself can be accessed using the {{jsxref("Operators/this", "this")}} operator in the global scope. In fact, the global scope consists of the properties of the global object, including inherited properties, if any.

+ +

Other objects in the global scope are either created by the user script or provided by the host application. The host objects available in browser contexts are documented in the API reference. For more information about the distinction between the DOM and core JavaScript, see JavaScript technologies overview.

+ +

Standard objects by category

+ +

Value properties

+ +

These global properties return a simple value; they have no properties or methods.

+ + + +

Function properties

+ +

These global functions—functions which are called globally rather than on an object—directly return their results to the caller.

+ + + +

Fundamental objects

+ +

These are the fundamental, basic objects upon which all other objects are based. This includes objects that represent general objects, functions, and errors.

+ + + +

Numbers and dates

+ +

These are the base objects representing numbers, dates, and mathematical calculations.

+ + + +

Text processing

+ +

These objects represent strings and support manipulating them.

+ + + +

Indexed collections

+ +

These objects represent collections of data which are ordered by an index value. This includes (typed) arrays and array-like constructs.

+ + + +

Keyed collections

+ +

These objects represent collections which use keys; these contain elements which are iterable in the order of insertion.

+ + + +

Vector collections

+ +

{{Glossary("SIMD")}} vector data types are objects where data is arranged into lanes.

+ + + +

Structured data

+ +

These objects represent and interact with structured data buffers and data coded using JavaScript Object Notation (JSON).

+ + + +

Control abstraction objects

+ + + +

Reflection

+ + + +

Internationalization

+ +

Additions to the ECMAScript core for language-sensitive functionalities.

+ + + +

Non-standard objects

+ + + +

Other

+ + +
+ +

 

diff --git a/files/he/web/javascript/reference/global_objects/object/assign/index.html b/files/he/web/javascript/reference/global_objects/object/assign/index.html new file mode 100644 index 0000000000..72d2b16579 --- /dev/null +++ b/files/he/web/javascript/reference/global_objects/object/assign/index.html @@ -0,0 +1,272 @@ +--- +title: Object.assign() +slug: Web/JavaScript/Reference/Global_Objects/Object/assign +translation_of: Web/JavaScript/Reference/Global_Objects/Object/assign +--- +

{{JSRef}}

+ +

מתודת Object.assign מעתיקה אובייקט על שלל {{jsxref("Object/propertyIsEnumerable", "מאפייניו", "", 1)} {{jsxref("Object/hasOwnProperty", "הקיימים", "", 1)}} לאובייקט אחר וממזגת אותם ביחד. המתודה מחזירה את האובייקט שאליו העתקנו את התכונות החדשות. 

+ +
תחביר
+ +
Object.assign(target, ...sources)
+ +

פרמטרים

+ +
+
target - אובייקט היעד
+
אובייקט היעד- האובייקט שאליו אנחנו מעתיקים את כל המאפיינים של האובייקט המקורי, כאשר הוא מחזיר את האובייקט אחרי המיזוג.
+
sources - אובייקט המקור
+
+
+ +
+
אובייקט המקור - האובייקט מכיל את המאפיינים שאנחנו רוצים להעתיק לאובייקט נוסף. 
+
+ +

Return value - הנתון התוצאה

+ +

The target object - האובייקט שאליו העתקנו את התכונות של האובייקט המקורי.

+ +

תיאור

+ +

מאפיינים באובייקט היעד ישוכתבו או ידרסו ע"י המאפיינים של אובייקט המקור אם הם חולקים את אותו ה-{{jsxref("Object/keys", "key", "", 1)}}. מאפיינים חדשים שיוגדו על מאפיינים משותפים (properties) בהמשך ידרסו גם באובייקט היעד וגם באופייקט המקור.

+ +

+ +

The Object.assign() method only copies enumerable and own properties from a source object to a target object. It uses [[Get]] on the source and [[Set]] on the target, so it will invoke getters and setters. Therefore it assigns properties, versus copying or defining new properties. This may make it unsuitable for merging new properties into a prototype if the merge sources contain getters.

+ +

For copying property definitions (including their enumerability) into prototypes, use {{jsxref("Object.getOwnPropertyDescriptor()")}} and {{jsxref("Object.defineProperty()")}} instead.

+ +

Both {{jsxref("String")}} and {{jsxref("Symbol")}} properties are copied.

+ +

In case of an error, for example if a property is non-writable, a {{jsxref("TypeError")}} is raised, and the target object is changed if any properties are added before the error is raised.

+ +
+

Note: Object.assign() does not throw on {{jsxref("null")}} or {{jsxref("undefined")}} sources.

+
+ +

Polyfill

+ +

This polyfill doesn't support symbol properties, since ES5 doesn't have symbols anyway:

+ +
if (typeof Object.assign !== 'function') {
+  // Must be writable: true, enumerable: false, configurable: true
+  Object.defineProperty(Object, "assign", {
+    value: function assign(target, varArgs) { // .length of function is 2
+      'use strict';
+      if (target === null || target === undefined) {
+        throw new TypeError('Cannot convert undefined or null to object');
+      }
+
+      var to = Object(target);
+
+      for (var index = 1; index < arguments.length; index++) {
+        var nextSource = arguments[index];
+
+        if (nextSource !== null && nextSource !== undefined) {
+          for (var nextKey in nextSource) {
+            // Avoid bugs when hasOwnProperty is shadowed
+            if (Object.prototype.hasOwnProperty.call(nextSource, nextKey)) {
+              to[nextKey] = nextSource[nextKey];
+            }
+          }
+        }
+      }
+      return to;
+    },
+    writable: true,
+    configurable: true
+  });
+}
+
+ +

Examples

+ +

Cloning an object

+ +
const obj = { a: 1 };
+const copy = Object.assign({}, obj);
+console.log(copy); // { a: 1 }
+
+ +

Warning for Deep Clone

+ +

For deep cloning, we need to use alternatives, because Object.assign() copies property values.

+ +

If the source value is a reference to an object, it only copies the reference value.

+ +
function test() {
+  'use strict';
+
+  let obj1 = { a: 0 , b: { c: 0}};
+  let obj2 = Object.assign({}, obj1);
+  console.log(JSON.stringify(obj2)); // { "a": 0, "b": { "c": 0}}
+
+  obj1.a = 1;
+  console.log(JSON.stringify(obj1)); // { "a": 1, "b": { "c": 0}}
+  console.log(JSON.stringify(obj2)); // { "a": 0, "b": { "c": 0}}
+
+  obj2.a = 2;
+  console.log(JSON.stringify(obj1)); // { "a": 1, "b": { "c": 0}}
+  console.log(JSON.stringify(obj2)); // { "a": 2, "b": { "c": 0}}
+
+  obj2.b.c = 3;
+  console.log(JSON.stringify(obj1)); // { "a": 1, "b": { "c": 3}}
+  console.log(JSON.stringify(obj2)); // { "a": 2, "b": { "c": 3}}
+
+  // Deep Clone
+  obj1 = { a: 0 , b: { c: 0}};
+  let obj3 = JSON.parse(JSON.stringify(obj1));
+  obj1.a = 4;
+  obj1.b.c = 4;
+  console.log(JSON.stringify(obj3)); // { "a": 0, "b": { "c": 0}}
+}
+
+test();
+ +

Merging objects

+ +
const o1 = { a: 1 };
+const o2 = { b: 2 };
+const o3 = { c: 3 };
+
+const obj = Object.assign(o1, o2, o3);
+console.log(obj); // { a: 1, b: 2, c: 3 }
+console.log(o1);  // { a: 1, b: 2, c: 3 }, target object itself is changed.
+ +

Merging objects with same properties

+ +
const o1 = { a: 1, b: 1, c: 1 };
+const o2 = { b: 2, c: 2 };
+const o3 = { c: 3 };
+
+const obj = Object.assign({}, o1, o2, o3);
+console.log(obj); // { a: 1, b: 2, c: 3 }
+ +

The properties are overwritten by other objects that have the same properties later in the parameters order.

+ +

Copying symbol-typed properties

+ +
const o1 = { a: 1 };
+const o2 = { [Symbol('foo')]: 2 };
+
+const obj = Object.assign({}, o1, o2);
+console.log(obj); // { a : 1, [Symbol("foo")]: 2 } (cf. bug 1207182 on Firefox)
+Object.getOwnPropertySymbols(obj); // [Symbol(foo)]
+
+ +

Properties on the prototype chain and non-enumerable properties cannot be copied

+ +
const obj = Object.create({ foo: 1 }, { // foo is on obj's prototype chain.
+  bar: {
+    value: 2  // bar is a non-enumerable property.
+  },
+  baz: {
+    value: 3,
+    enumerable: true  // baz is an own enumerable property.
+  }
+});
+
+const copy = Object.assign({}, obj);
+console.log(copy); // { baz: 3 }
+
+ +

Primitives will be wrapped to objects

+ +
const v1 = 'abc';
+const v2 = true;
+const v3 = 10;
+const v4 = Symbol('foo');
+
+const obj = Object.assign({}, v1, null, v2, undefined, v3, v4);
+// Primitives will be wrapped, null and undefined will be ignored.
+// Note, only string wrappers can have own enumerable properties.
+console.log(obj); // { "0": "a", "1": "b", "2": "c" }
+
+ +

Exceptions will interrupt the ongoing copying task

+ +
const target = Object.defineProperty({}, 'foo', {
+  value: 1,
+  writable: false
+}); // target.foo is a read-only property
+
+Object.assign(target, { bar: 2 }, { foo2: 3, foo: 3, foo3: 3 }, { baz: 4 });
+// TypeError: "foo" is read-only
+// The Exception is thrown when assigning target.foo
+
+console.log(target.bar);  // 2, the first source was copied successfully.
+console.log(target.foo2); // 3, the first property of the second source was copied successfully.
+console.log(target.foo);  // 1, exception is thrown here.
+console.log(target.foo3); // undefined, assign method has finished, foo3 will not be copied.
+console.log(target.baz);  // undefined, the third source will not be copied either.
+
+ +

Copying accessors

+ +
const obj = {
+  foo: 1,
+  get bar() {
+    return 2;
+  }
+};
+
+let copy = Object.assign({}, obj);
+console.log(copy);
+// { foo: 1, bar: 2 }
+// The value of copy.bar is obj.bar's getter's return value.
+
+// This is an assign function that copies full descriptors
+function completeAssign(target, ...sources) {
+  sources.forEach(source => {
+    let descriptors = Object.keys(source).reduce((descriptors, key) => {
+      descriptors[key] = Object.getOwnPropertyDescriptor(source, key);
+      return descriptors;
+    }, {});
+
+    // By default, Object.assign copies enumerable Symbols, too
+    Object.getOwnPropertySymbols(source).forEach(sym => {
+      let descriptor = Object.getOwnPropertyDescriptor(source, sym);
+      if (descriptor.enumerable) {
+        descriptors[sym] = descriptor;
+      }
+    });
+    Object.defineProperties(target, descriptors);
+  });
+  return target;
+}
+
+copy = completeAssign({}, obj);
+console.log(copy);
+// { foo:1, get bar() { return 2 } }
+
+ +

Specifications

+ + + + + + + + + + + + +
Specification
{{SpecName('ESDraft', '#sec-object.assign', 'Object.assign')}}
+ +

Browser compatibility

+ + + +

{{Compat("javascript.builtins.Object.assign")}}

+ +

See also

+ + diff --git a/files/he/web/javascript/reference/global_objects/object/index.html b/files/he/web/javascript/reference/global_objects/object/index.html new file mode 100644 index 0000000000..9feed92ddc --- /dev/null +++ b/files/he/web/javascript/reference/global_objects/object/index.html @@ -0,0 +1,184 @@ +--- +title: Object +slug: Web/JavaScript/Reference/Global_Objects/Object +tags: + - Constructor + - JavaScript + - NeedsTranslation + - Object + - TopicStub +translation_of: Web/JavaScript/Reference/Global_Objects/Object +--- +
{{JSRef}}
+ +

The Object constructor creates an object wrapper.

+ +

Syntax

+ +
// Object initialiser or literal
+{ [ nameValuePair1[, nameValuePair2[, ...nameValuePairN] ] ] }
+
+// Called as a constructor
+new Object([value])
+ +

Parameters

+ +
+
nameValuePair1, nameValuePair2, ... nameValuePairN
+
Pairs of names (strings) and values (any value) where the name is separated from the value by a colon.
+
value
+
Any value.
+
+ +

Description

+ +

The Object constructor creates an object wrapper for the given value. If the value is {{jsxref("null")}} or {{jsxref("undefined")}}, it will create and return an empty object, otherwise, it will return an object of a Type that corresponds to the given value. If the value is an object already, it will return the value.

+ +

When called in a non-constructor context, Object behaves identically to new Object().

+ +

See also the object initializer / literal syntax.

+ +

Properties of the Object constructor

+ +
+
Object.length
+
Has a value of 1.
+
{{jsxref("Object.prototype")}}
+
Allows the addition of properties to all objects of type Object.
+
+ +

Methods of the Object constructor

+ +
+
{{jsxref("Object.assign()")}}
+
Copies the values of all enumerable own properties from one or more source objects to a target object.
+
{{jsxref("Object.create()")}}
+
Creates a new object with the specified prototype object and properties.
+
{{jsxref("Object.defineProperty()")}}
+
Adds the named property described by a given descriptor to an object.
+
{{jsxref("Object.defineProperties()")}}
+
Adds the named properties described by the given descriptors to an object.
+
{{jsxref("Object.entries()")}}
+
Returns an array containing all of the [key, value] pairs of a given object's own enumerable string properties.
+
{{jsxref("Object.freeze()")}}
+
Freezes an object: other code can't delete or change any properties.
+
{{jsxref("Object.fromEntries()")}}
+
Returns a new object from an iterable of key-value pairs (reverses {{jsxref("Object.entries")}}).
+
{{jsxref("Object.getOwnPropertyDescriptor()")}}
+
Returns a property descriptor for a named property on an object.
+
{{jsxref("Object.getOwnPropertyDescriptors()")}}
+
Returns an object containing all own property descriptors for an object.
+
{{jsxref("Object.getOwnPropertyNames()")}}
+
Returns an array containing the names of all of the given object's own enumerable and non-enumerable properties.
+
{{jsxref("Object.getOwnPropertySymbols()")}}
+
Returns an array of all symbol properties found directly upon a given object.
+
{{jsxref("Object.getPrototypeOf()")}}
+
Returns the prototype of the specified object.
+
{{jsxref("Object.is()")}}
+
Compares if two values are the same value. Equates all NaN values (which differs from both Abstract Equality Comparison and Strict Equality Comparison).
+
{{jsxref("Object.isExtensible()")}}
+
Determines if extending of an object is allowed.
+
{{jsxref("Object.isFrozen()")}}
+
Determines if an object was frozen.
+
{{jsxref("Object.isSealed()")}}
+
Determines if an object is sealed.
+
{{jsxref("Object.keys()")}}
+
Returns an array containing the names of all of the given object's own enumerable string properties.
+
{{jsxref("Object.preventExtensions()")}}
+
Prevents any extensions of an object.
+
{{jsxref("Object.seal()")}}
+
Prevents other code from deleting properties of an object.
+
{{jsxref("Object.setPrototypeOf()")}}
+
Sets the prototype (i.e., the internal [[Prototype]] property).
+
{{jsxref("Object.values()")}}
+
Returns an array containing the values that correspond to all of a given object's own enumerable string properties.
+
+ +

Object instances and Object prototype object

+ +

All objects in JavaScript are descended from Object; all objects inherit methods and properties from {{jsxref("Object.prototype")}}, although they may be overridden. For example, other constructors' prototypes override the constructor property and provide their own toString() methods. Changes to the Object prototype object are propagated to all objects unless the properties and methods subject to those changes are overridden further along the prototype chain.

+ +

Properties

+ +
{{page('/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/prototype', 'Properties') }}
+ +

Methods

+ +
{{page('/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/prototype', 'Methods') }}
+ +

Deleting a property from an object

+ +

There isn't any method in an Object itself to delete its own properties (e.g. like Map.prototype.delete()). To do so one has to use the delete operator.

+ +

Examples

+ +

Using Object given undefined and null types

+ +

The following examples store an empty Object object in o:

+ +
var o = new Object();
+
+ +
var o = new Object(undefined);
+
+ +
var o = new Object(null);
+
+ +

Using Object to create Boolean objects

+ +

The following examples store {{jsxref("Boolean")}} objects in o:

+ +
// equivalent to o = new Boolean(true);
+var o = new Object(true);
+
+ +
// equivalent to o = new Boolean(false);
+var o = new Object(Boolean());
+
+ +

Specifications

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
SpecificationStatusComment
{{SpecName('ES1')}}{{Spec2('ES1')}}Initial definition. Implemented in JavaScript 1.0.
{{SpecName('ES5.1', '#sec-15.2', 'Object')}}{{Spec2('ES5.1')}} 
{{SpecName('ES6', '#sec-object-objects', 'Object')}}{{Spec2('ES6')}}Added Object.assign, Object.getOwnPropertySymbols, Object.setPrototypeOf, Object.is
{{SpecName('ESDraft', '#sec-object-objects', 'Object')}}{{Spec2('ESDraft')}}Added Object.entries, Object.values and Object.getOwnPropertyDescriptors.
+ +

Browser compatibility

+ +
+ + +

{{Compat("javascript.builtins.Object")}}

+
+ +

See also

+ + diff --git a/files/he/web/javascript/reference/global_objects/promise/index.html b/files/he/web/javascript/reference/global_objects/promise/index.html new file mode 100644 index 0000000000..1f1c71827c --- /dev/null +++ b/files/he/web/javascript/reference/global_objects/promise/index.html @@ -0,0 +1,244 @@ +--- +title: Promise +slug: Web/JavaScript/Reference/Global_Objects/Promise +translation_of: Web/JavaScript/Reference/Global_Objects/Promise +--- +
{{JSRef}}
+ +

The Promise object represents the eventual completion (or failure) of an asynchronous operation, and its resulting value.

+ +
+

Note: This article describes the Promise constructor and the methods and properties of such objects. To learn about the way promises work and how you can use them, we advise you to read Using promises first. The constructor is primarily used to wrap functions that do not already support promises.

+
+ +
{{EmbedInteractiveExample("pages/js/promise-constructor.html")}}
+ + + +

תחביר

+ +
new Promise( /* executor */ function(resolve, reject) { ... } );
+ +

פרמטרים

+ +
+
executor
+
A function that is passed with the arguments resolve and reject. The executor function is executed immediately by the Promise implementation, passing resolve and reject functions (the executor is called before the Promise constructor even returns the created object). The resolve and reject functions, when called, resolve or reject the promise, respectively. The executor normally initiates some asynchronous work, and then, once that completes, either calls the resolve function to resolve the promise or else rejects it if an error occurred. If an error is thrown in the executor function, the promise is rejected. The return value of the executor is ignored.
+
+ +

תיאור

+ +

A Promise is a proxy for a value not necessarily known when the promise is created. It allows you to associate handlers with an asynchronous action's eventual success value or failure reason. This lets asynchronous methods return values like synchronous methods: instead of immediately returning the final value, the asynchronous method returns a promise to supply the value at some point in the future.

+ +

A Promise is in one of these states:

+ + + +

A pending promise can either be fulfilled with a value, or rejected with a reason (error). When either of these options happens, the associated handlers queued up by a promise's then method are called. (If the promise has already been fulfilled or rejected when a corresponding handler is attached, the handler will be called, so there is no race condition between an asynchronous operation completing and its handlers being attached.)

+ +

As the {{jsxref("Promise.then", "Promise.prototype.then()")}} and {{jsxref("Promise.catch", "Promise.prototype.catch()")}} methods return promises, they can be chained.

+ +

+ +
+

Not to be confused with: Several other languages have mechanisms for lazy evaluation and deferring a computation, which they also call "promises", e.g. Scheme. Promises in JavaScript represent processes which are already happening, which can be chained with callback functions. If you are looking to lazily evaluate an expression, consider the arrow function with no arguments: f = () => expression to create the lazily-evaluated expression, and f() to evaluate.

+
+ +
+

Note: A promise is said to be settled if it is either fulfilled or rejected, but not pending. You will also hear the term resolved used with promises — this means that the promise is settled or “locked in” to match the state of another promise. States and fates contains more details about promise terminology.

+
+ +

מאפיינים

+ +
+
Promise.length
+
Length property whose value is always 1 (number of constructor arguments).
+
{{jsxref("Promise.prototype")}}
+
Represents the prototype for the Promise constructor.
+
+ +

Methods

+ +
+
{{jsxref("Promise.all", "Promise.all(iterable)")}}
+
Returns a promise that either fulfills when all of the promises in the iterable argument have fulfilled or rejects as soon as one of the promises in the iterable argument rejects. If the returned promise fulfills, it is fulfilled with an array of the values from the fulfilled promises in the same order as defined in the iterable. If the returned promise rejects, it is rejected with the reason from the first promise in the iterable that rejected. This method can be useful for aggregating results of multiple promises.
+
{{jsxref("Promise.race", "Promise.race(iterable)")}}
+
Returns a promise that fulfills or rejects as soon as one of the promises in the iterable fulfills or rejects, with the value or reason from that promise.
+
{{jsxref("Promise.reject", "Promise.reject(reason)")}}
+
Returns a Promise object that is rejected with the given reason.
+
{{jsxref("Promise.resolve", "Promise.resolve(value)")}}
+
Returns a Promise object that is resolved with the given value. If the value is a thenable (i.e. has a then method), the returned promise will "follow" that thenable, adopting its eventual state; otherwise the returned promise will be fulfilled with the value. Generally, if you don't know if a value is a promise or not, {{jsxref("Promise.resolve", "Promise.resolve(value)")}} it instead and work with the return value as a promise.
+
+ +

Promise prototype

+ +

Properties

+ +

{{page('en-US/Web/JavaScript/Reference/Global_Objects/Promise/prototype','Properties')}}

+ +

Methods

+ +

{{page('en-US/Web/JavaScript/Reference/Global_Objects/Promise/prototype','Methods')}}

+ +

Creating a Promise

+ +

A Promise object is created using the new keyword and its constructor. This constructor takes as its argument a function, called the "executor function". This function should take two functions as parameters. The first of these functions (resolve) is called when the asynchronous task completes successfully and returns the results of the task as a value. The second (reject) is called when the task fails, and returns the reason for failure, which is typically an error object.

+ +
const myFirstPromise = new Promise((resolve, reject) => {
+  // do something asynchronous which eventually calls either:
+  //
+  //   resolve(someValue); // fulfilled
+  // or
+  //   reject("failure reason"); // rejected
+});
+
+ +

To provide a function with promise functionality, simply have it return a promise:

+ +
function myAsyncFunction(url) {
+  return new Promise((resolve, reject) => {
+    const xhr = new XMLHttpRequest();
+    xhr.open("GET", url);
+    xhr.onload = () => resolve(xhr.responseText);
+    xhr.onerror = () => reject(xhr.statusText);
+    xhr.send();
+  });
+}
+ +

דוגמאות

+ +

דוגמה בסיסית

+ +
let myFirstPromise = new Promise((resolve, reject) => {
+  // We call resolve(...) when what we were doing asynchronously was successful, and reject(...) when it failed.
+  // In this example, we use setTimeout(...) to simulate async code.
+  // In reality, you will probably be using something like XHR or an HTML5 API.
+  setTimeout(function(){
+    resolve("Success!"); // Yay! Everything went well!
+  }, 250);
+});
+
+myFirstPromise.then((successMessage) => {
+  // successMessage is whatever we passed in the resolve(...) function above.
+  // It doesn't have to be a string, but if it is only a succeed message, it probably will be.
+  console.log("Yay! " + successMessage);
+});
+
+ +

דוגמה מתקדמת

+ + + +

This small example shows the mechanism of a Promise. The testPromise() method is called each time the {{HTMLElement("button")}} is clicked. It creates a promise that will be fulfilled, using {{domxref("window.setTimeout()")}}, to the promise count (number starting from 1) every 1-3 seconds, at random. The Promise() constructor is used to create the promise.

+ +

The fulfillment of the promise is simply logged, via a fulfill callback set using {{jsxref("Promise.prototype.then()","p1.then()")}}. A few logs show how the synchronous part of the method is decoupled from the asynchronous completion of the promise.

+ +
'use strict';
+var promiseCount = 0;
+
+function testPromise() {
+    let thisPromiseCount = ++promiseCount;
+
+    let log = document.getElementById('log');
+    log.insertAdjacentHTML('beforeend', thisPromiseCount +
+        ') Started (<small>Sync code started</small>)<br/>');
+
+    // We make a new promise: we promise a numeric count of this promise, starting from 1 (after waiting 3s)
+    let p1 = new Promise(
+        // The executor function is called with the ability to resolve or
+        // reject the promise
+       (resolve, reject) => {
+            log.insertAdjacentHTML('beforeend', thisPromiseCount +
+                ') Promise started (<small>Async code started</small>)<br/>');
+            // This is only an example to create asynchronism
+            window.setTimeout(
+                function() {
+                    // We fulfill the promise !
+                    resolve(thisPromiseCount);
+                }, Math.random() * 2000 + 1000);
+        }
+    );
+
+    // We define what to do when the promise is resolved with the then() call,
+    // and what to do when the promise is rejected with the catch() call
+    p1.then(
+        // Log the fulfillment value
+        function(val) {
+            log.insertAdjacentHTML('beforeend', val +
+                ') Promise fulfilled (<small>Async code terminated</small>)<br/>');
+        }).catch(
+        // Log the rejection reason
+       (reason) => {
+            console.log('Handle rejected promise ('+reason+') here.');
+        });
+
+    log.insertAdjacentHTML('beforeend', thisPromiseCount +
+        ') Promise made (<small>Sync code terminated</small>)<br/>');
+}
+ + + +

This example is started by clicking the button. You need a browser that supports Promise. By clicking the button several times in a short amount of time, you'll even see the different promises being fulfilled one after another.

+ +

{{EmbedLiveSample("Advanced_Example", "500", "200")}}

+ +

טעינת תמונה באמצעות XHR

+ +

Another simple example using Promise and {{domxref("XMLHttpRequest")}} to load an image is available at the MDN GitHub js-examples repository. You can also see it in action. Each step is commented and allows you to follow the Promise and XHR architecture closely.

+ +

מפרט

+ + + + + + + + + + + + + + + + + + + +
SpecificationStatusComment
{{SpecName('ES2015', '#sec-promise-objects', 'Promise')}}{{Spec2('ES2015')}}Initial definition in an ECMA standard.
{{SpecName('ESDraft', '#sec-promise-objects', 'Promise')}}{{Spec2('ESDraft')}} 
+ +

תאימות דפדפן

+ + + +

{{Compat("javascript.builtins.Promise")}}

+ +

ראה גם

+ + diff --git a/files/he/web/javascript/reference/global_objects/string/index.html b/files/he/web/javascript/reference/global_objects/string/index.html new file mode 100644 index 0000000000..8b8911749e --- /dev/null +++ b/files/he/web/javascript/reference/global_objects/string/index.html @@ -0,0 +1,314 @@ +--- +title: 'String: מחרוזת' +slug: Web/JavaScript/Reference/Global_Objects/String +tags: + - ECMAScript 2015 + - JavaScript + - NeedsTranslation + - Reference + - String + - TopicStub +translation_of: Web/JavaScript/Reference/Global_Objects/String +--- +
{{JSRef}}
+ +

The String global object is a constructor for strings or a sequence of characters.

+ +

תחביר

+ +

String literals take the forms:

+ +
'string text'
+"string text"
+"中文 español Deutsch English देवनागरी العربية português বাংলা русский 日本語 ਪੰਜਾਬੀ 한국어 தமிழ் עברית"
+ +

Strings can also be created using the String global object directly:

+ +
String(thing)
+ +

Parameters

+ +
+
thing
+
Anything to be converted to a string.
+
+ +

Template literals

+ +

Starting with ECMAScript 2015, string literals can also be so-called Template literals:

+ +
`hello world`
+`hello!
+ world!`
+`hello ${who}`
+escape `<a>${who}</a>`
+ +
+
+ +

Escape notation

+ +

Besides regular, printable characters, special characters can be encoded using escape notation:

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
CodeOutput
\XXXan octal Latin-1 character.
\'single quote
\"double quote
\\backslash
\nnew line
\rcarriage return
\vvertical tab
\ttab
\bbackspace
\fform feed
\uXXXXunicode codepoint
\u{X} ... \u{XXXXXX}unicode codepoint {{experimental_inline}}
\xXXthe Latin-1 character
+ +
+

Unlike some other languages, JavaScript makes no distinction between single-quoted strings and double-quoted strings; therefore, the escape sequences above work in strings created with either single or double quotes.

+
+ +
+
+ +

Long literal strings

+ +

Sometimes, your code will include strings which are very long. Rather than having lines that go on endlessly, or wrap at the whim of your editor, you may wish to specifically break the string into multiple lines in the source code without affecting the actual string contents. There are two ways you can do this.

+ +

You can use the + operator to append multiple strings together, like this:

+ +
let longString = "This is a very long string which needs " +
+                 "to wrap across multiple lines because " +
+                 "otherwise my code is unreadable.";
+
+ +

Or you can use the backslash character ("\") at the end of each line to indicate that the string will continue on the next line. Make sure there is no space or any other character after the backslash (except for a line break), or as an indent; otherwise it will not work. That form looks like this:

+ +
let longString = "This is a very long string which needs \
+to wrap across multiple lines because \
+otherwise my code is unreadable.";
+
+ +

Both of these result in identical strings being created.

+ +

תיאור

+ +

Strings are useful for holding data that can be represented in text form. Some of the most-used operations on strings are to check their {{jsxref("String.length", "length")}}, to build and concatenate them using the + and += string operators, checking for the existence or location of substrings with the {{jsxref("String.prototype.indexOf()", "indexOf()")}} method, or extracting substrings with the {{jsxref("String.prototype.substring()", "substring()")}} method.

+ +

Character access

+ +

There are two ways to access an individual character in a string. The first is the {{jsxref("String.prototype.charAt()", "charAt()")}} method:

+ +
return 'cat'.charAt(1); // returns "a"
+
+ +

The other way (introduced in ECMAScript 5) is to treat the string as an array-like object, where individual characters correspond to a numerical index:

+ +
return 'cat'[1]; // returns "a"
+
+ +

For character access using bracket notation, attempting to delete or assign a value to these properties will not succeed. The properties involved are neither writable nor configurable. (See {{jsxref("Object.defineProperty()")}} for more information.)

+ +

Comparing strings

+ +

C developers have the strcmp() function for comparing strings. In JavaScript, you just use the less-than and greater-than operators:

+ +
var a = 'a';
+var b = 'b';
+if (a < b) { // true
+  console.log(a + ' is less than ' + b);
+} else if (a > b) {
+  console.log(a + ' is greater than ' + b);
+} else {
+  console.log(a + ' and ' + b + ' are equal.');
+}
+
+ +

A similar result can be achieved using the {{jsxref("String.prototype.localeCompare()", "localeCompare()")}} method inherited by String instances.

+ +

Distinction between string primitives and String objects

+ +

Note that JavaScript distinguishes between String objects and primitive string values. (The same is true of {{jsxref("Boolean")}} and {{jsxref("Global_Objects/Number", "Numbers")}}.)

+ +

String literals (denoted by double or single quotes) and strings returned from String calls in a non-constructor context (i.e., without using the {{jsxref("Operators/new", "new")}} keyword) are primitive strings. JavaScript automatically converts primitives to String objects, so that it's possible to use String object methods for primitive strings. In contexts where a method is to be invoked on a primitive string or a property lookup occurs, JavaScript will automatically wrap the string primitive and call the method or perform the property lookup.

+ +
var s_prim = 'foo';
+var s_obj = new String(s_prim);
+
+console.log(typeof s_prim); // Logs "string"
+console.log(typeof s_obj);  // Logs "object"
+
+ +

String primitives and String objects also give different results when using {{jsxref("Global_Objects/eval", "eval()")}}. Primitives passed to eval are treated as source code; String objects are treated as all other objects are, by returning the object. For example:

+ +
var s1 = '2 + 2';             // creates a string primitive
+var s2 = new String('2 + 2'); // creates a String object
+console.log(eval(s1));        // returns the number 4
+console.log(eval(s2));        // returns the string "2 + 2"
+
+ +

For these reasons, the code may break when it encounters String objects when it expects a primitive string instead, although generally, authors need not worry about the distinction.

+ +

A String object can always be converted to its primitive counterpart with the {{jsxref("String.prototype.valueOf()", "valueOf()")}} method.

+ +
console.log(eval(s2.valueOf())); // returns the number 4
+
+ +
Note: For another possible approach to strings in JavaScript, please read the article about StringView — a C-like representation of strings based on typed arrays.
+ +

מאפיינים

+ +
+
{{jsxref("String.prototype")}}
+
Allows the addition of properties to a String object.
+
+ +

Methods

+ +
+
{{jsxref("String.fromCharCode()")}}
+
Returns a string created by using the specified sequence of Unicode values.
+
{{jsxref("String.fromCodePoint()")}}
+
Returns a string created by using the specified sequence of code points.
+
{{jsxref("String.raw()")}} {{experimental_inline}}
+
Returns a string created from a raw template string.
+
+ +

String generic methods

+ +
+

String generics are non-standard, deprecated and will get removed near future.

+
+ +

The String instance methods are also available in Firefox as of JavaScript 1.6 (not part of the ECMAScript standard) on the String object for applying String methods to any object:

+ +
var num = "15";
+console.log(num.replace("5", "2"));
+
+ +

For migrating away from String generics, see also Warning: String.x is deprecated; use String.prototype.x instead.

+ +

{{jsxref("Global_Objects/Array", "Generics", "#Array_generic_methods", 1)}} are also available on {{jsxref("Array")}} methods.

+ +

String instances

+ +

Properties

+ +
{{page('/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/prototype', 'Properties')}}
+ +

Methods

+ +

Methods unrelated to HTML

+ +
{{page('/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/prototype', 'Methods_unrelated_to_HTML')}}
+ +

HTML wrapper methods

+ +
{{page('/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/prototype', 'HTML_wrapper_methods')}}
+ +

דוגמאות

+ +

String conversion

+ +

It's possible to use String as a more reliable {{jsxref("String.prototype.toString()", "toString()")}} alternative, as it works when used on {{jsxref("null")}}, {{jsxref("undefined")}}, and on {{jsxref("Symbol", "symbols")}}. For example:

+ +
var outputStrings = [];
+for (var i = 0, n = inputValues.length; i < n; ++i) {
+  outputStrings.push(String(inputValues[i]));
+}
+
+ +

Specifications

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
SpecificationStatusComment
{{SpecName('ES1')}}{{Spec2('ES1')}}Initial definition.
{{SpecName('ES5.1', '#sec-15.5', 'String')}}{{Spec2('ES5.1')}} 
{{SpecName('ES2015', '#sec-string-objects', 'String')}}{{Spec2('ES2015')}} 
{{SpecName('ESDraft', '#sec-string-objects', 'String')}}{{Spec2('ESDraft')}} 
+ +

תאימות דפדפן

+ + + +

{{Compat("javascript.builtins.String",2)}}

+ +

ראה גם

+ + -- cgit v1.2.3-54-g00ecf