From 074785cea106179cb3305637055ab0a009ca74f2 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:42:52 -0500 Subject: initial commit --- .../reference/global_objects/uint8array/index.html | 199 +++++++++++++++++++++ 1 file changed, 199 insertions(+) create mode 100644 files/ru/web/javascript/reference/global_objects/uint8array/index.html (limited to 'files/ru/web/javascript/reference/global_objects/uint8array') diff --git a/files/ru/web/javascript/reference/global_objects/uint8array/index.html b/files/ru/web/javascript/reference/global_objects/uint8array/index.html new file mode 100644 index 0000000000..8992a49394 --- /dev/null +++ b/files/ru/web/javascript/reference/global_objects/uint8array/index.html @@ -0,0 +1,199 @@ +--- +title: Uint8Array +slug: Web/JavaScript/Reference/Global_Objects/Uint8Array +translation_of: Web/JavaScript/Reference/Global_Objects/Uint8Array +--- +
{{JSRef}}
+ +

Объект Uint8Array представляет типизированный массив 8-разрядных целых беззнаковых значений. Содержимое инициализируется значением 0. Создав экземпляр Uint8Array, возможно получить доступ к элементам массива, используя методы объекта или стандартный синтаксис доступа к элементу массива по его индексу (с помощью скобочной нотации).

+ +

Syntax

+ +
new Uint8Array(); // new in ES2017
+new Uint8Array(length);
+new Uint8Array(typedArray);
+new Uint8Array(object);
+new Uint8Array(buffer [, byteOffset [, length]]);
+ +

For more information about the constructor syntax and the parameters, see TypedArray.

+ +

Properties

+ +
+
{{jsxref("TypedArray.BYTES_PER_ELEMENT", "Uint8Array.BYTES_PER_ELEMENT")}}
+
Returns a number value of the element size. 1 in the case of an Uint8Array.
+
Uint8Array.length
+
Static length property whose value is 0. For the actual length (number of elements), see {{jsxref("TypedArray.prototype.length", "Uint8Array.prototype.length")}}.
+
{{jsxref("TypedArray.name", "Uint8Array.name")}}
+
Returns the string value of the constructor name. In the case of the Uint8Array type: "Uint8Array".
+
{{jsxref("TypedArray.prototype", "Uint8Array.prototype")}}
+
Prototype for the TypedArray objects.
+
+ +

Methods

+ +
+
{{jsxref("TypedArray.from", "Uint8Array.from()")}}
+
Creates a new Uint8Array from an array-like or iterable object. See also {{jsxref("Array.from()")}}.
+
{{jsxref("TypedArray.of", "Uint8Array.of()")}}
+
Creates a new Uint8Array with a variable number of arguments. See also {{jsxref("Array.of()")}}.
+
+ +

Uint8Array prototype

+ +

All Uint8Array objects inherit from {{jsxref("TypedArray.prototype", "%TypedArray%.prototype")}}.

+ +

Properties

+ +
+
Uint8Array.prototype.constructor
+
Returns the function that created an instance's prototype. This is the Uint8Array constructor by default.
+
{{jsxref("TypedArray.prototype.buffer", "Uint8Array.prototype.buffer")}} {{readonlyInline}}
+
Returns the {{jsxref("ArrayBuffer")}} referenced by the Uint8Array Fixed at construction time and thus read only.
+
{{jsxref("TypedArray.prototype.byteLength", "Uint8Array.prototype.byteLength")}} {{readonlyInline}}
+
Returns the length (in bytes) of the Uint8Array. Fixed at construction time and thus read only.
+
{{jsxref("TypedArray.prototype.byteOffset", "Uint8Array.prototype.byteOffset")}} {{readonlyInline}}
+
Returns the offset (in bytes) of the Uint8Array from the start of its {{jsxref("ArrayBuffer")}}. Fixed at construction time and thus read only.
+
{{jsxref("TypedArray.prototype.length", "Uint8Array.prototype.length")}} {{readonlyInline}}
+
Returns the number of elements held in the Uint8Array. Fixed at construction time and thus read only.
+
+ +

Methods

+ +
+
{{jsxref("TypedArray.copyWithin", "Uint8Array.prototype.copyWithin()")}}
+
Copies a sequence of array elements within the array. See also {{jsxref("Array.prototype.copyWithin()")}}.
+
{{jsxref("TypedArray.entries", "Uint8Array.prototype.entries()")}}
+
Returns a new Array Iterator object that contains the key/value pairs for each index in the array. See also {{jsxref("Array.prototype.entries()")}}.
+
{{jsxref("TypedArray.every", "Uint8Array.prototype.every()")}}
+
Tests whether all elements in the array pass the test provided by a function. See also {{jsxref("Array.prototype.every()")}}.
+
{{jsxref("TypedArray.fill", "Uint8Array.prototype.fill()")}}
+
Fills all the elements of an array from a start index to an end index with a static value. See also {{jsxref("Array.prototype.fill()")}}.
+
{{jsxref("TypedArray.filter", "Uint8Array.prototype.filter()")}}
+
Creates a new array with all of the elements of this array for which the provided filtering function returns true. See also {{jsxref("Array.prototype.filter()")}}.
+
{{jsxref("TypedArray.find", "Uint8Array.prototype.find()")}}
+
Returns the found value in the array, if an element in the array satisfies the provided testing function or undefined if not found. See also {{jsxref("Array.prototype.find()")}}.
+
{{jsxref("TypedArray.findIndex", "Uint8Array.prototype.findIndex()")}}
+
Returns the found index in the array, if an element in the array satisfies the provided testing function or -1 if not found. See also {{jsxref("Array.prototype.findIndex()")}}.
+
{{jsxref("TypedArray.forEach", "Uint8Array.prototype.forEach()")}}
+
Calls a function for each element in the array. See also {{jsxref("Array.prototype.forEach()")}}.
+
{{jsxref("TypedArray.includes", "Uint8Array.prototype.includes()")}} {{experimental_inline}}
+
Determines whether a typed array includes a certain element, returning true or false as appropriate. See also {{jsxref("Array.prototype.includes()")}}.
+
{{jsxref("TypedArray.indexOf", "Uint8Array.prototype.indexOf()")}}
+
Returns the first (least) index of an element within the array equal to the specified value, or -1 if none is found. See also {{jsxref("Array.prototype.indexOf()")}}.
+
{{jsxref("TypedArray.join", "Uint8Array.prototype.join()")}}
+
Joins all elements of an array into a string. See also {{jsxref("Array.prototype.join()")}}.
+
{{jsxref("TypedArray.keys", "Uint8Array.prototype.keys()")}}
+
Returns a new Array Iterator that contains the keys for each index in the array. See also {{jsxref("Array.prototype.keys()")}}.
+
{{jsxref("TypedArray.lastIndexOf", "Uint8Array.prototype.lastIndexOf()")}}
+
Returns the last (greatest) index of an element within the array equal to the specified value, or -1 if none is found. See also {{jsxref("Array.prototype.lastIndexOf()")}}.
+
{{jsxref("TypedArray.map", "Uint8Array.prototype.map()")}}
+
Creates a new array with the results of calling a provided function on every element in this array. See also {{jsxref("Array.prototype.map()")}}.
+
{{jsxref("TypedArray.move", "Uint8Array.prototype.move()")}} {{non-standard_inline}} {{unimplemented_inline}}
+
Former non-standard version of {{jsxref("TypedArray.copyWithin", "Uint8Array.prototype.copyWithin()")}}.
+
{{jsxref("TypedArray.reduce", "Uint8Array.prototype.reduce()")}}
+
Apply a function against an accumulator and each value of the array (from left-to-right) as to reduce it to a single value. See also {{jsxref("Array.prototype.reduce()")}}.
+
{{jsxref("TypedArray.reduceRight", "Uint8Array.prototype.reduceRight()")}}
+
Apply a function against an accumulator and each value of the array (from right-to-left) as to reduce it to a single value. See also {{jsxref("Array.prototype.reduceRight()")}}.
+
{{jsxref("TypedArray.reverse", "Uint8Array.prototype.reverse()")}}
+
Reverses the order of the elements of an array — the first becomes the last, and the last becomes the first. See also {{jsxref("Array.prototype.reverse()")}}.
+
{{jsxref("TypedArray.set", "Uint8Array.prototype.set()")}}
+
Stores multiple values in the typed array, reading input values from a specified array.
+
{{jsxref("TypedArray.slice", "Uint8Array.prototype.slice()")}}
+
Extracts a section of an array and returns a new array. See also {{jsxref("Array.prototype.slice()")}}.
+
{{jsxref("TypedArray.some", "Uint8Array.prototype.some()")}}
+
Returns true if at least one element in this array satisfies the provided testing function. See also {{jsxref("Array.prototype.some()")}}.
+
{{jsxref("TypedArray.sort", "Uint8Array.prototype.sort()")}}
+
Sorts the elements of an array in place and returns the array. See also {{jsxref("Array.prototype.sort()")}}.
+
{{jsxref("TypedArray.subarray", "Uint8Array.prototype.subarray()")}}
+
Returns a new Uint8Array from the given start and end element index.
+
{{jsxref("TypedArray.values", "Uint8Array.prototype.values()")}}
+
Returns a new Array Iterator object that contains the values for each index in the array. See also {{jsxref("Array.prototype.values()")}}.
+
{{jsxref("TypedArray.toLocaleString", "Uint8Array.prototype.toLocaleString()")}}
+
Returns a localized string representing the array and its elements. See also {{jsxref("Array.prototype.toLocaleString()")}}.
+
{{jsxref("TypedArray.toString", "Uint8Array.prototype.toString()")}}
+
Returns a string representing the array and its elements. See also {{jsxref("Array.prototype.toString()")}}.
+
{{jsxref("TypedArray.@@iterator", "Uint8Array.prototype[@@iterator]()")}}
+
Returns a new Array Iterator object that contains the values for each index in the array.
+
+ +

Examples

+ +

Different ways to create a Uint8Array:

+ +
// From a length
+var uint8 = new Uint8Array(2);
+uint8[0] = 42;
+console.log(uint8[0]); // 42
+console.log(uint8.length); // 2
+console.log(uint8.BYTES_PER_ELEMENT); // 1
+
+// From an array
+var arr = new Uint8Array([21,31]);
+console.log(arr[1]); // 31
+
+// From another TypedArray
+var x = new Uint8Array([21, 31]);
+var y = new Uint8Array(x);
+console.log(y[0]); // 21
+
+// From an ArrayBuffer
+var buffer = new ArrayBuffer(8);
+var z = new Uint8Array(buffer, 1, 4);
+
+// From an iterable
+var iterable = function*(){ yield* [1,2,3]; }();
+var uint8 = new Uint8Array(iterable);
+// Uint8Array[1, 2, 3]
+
+ +

Specifications

+ + + + + + + + + + + + + + + + + + + + + + + + +
SpecificationStatusComment
{{SpecName('Typed Array')}}{{Spec2('Typed Array')}}Superseded by ECMAScript 6.
{{SpecName('ES6', '#table-49', 'TypedArray constructors')}}{{Spec2('ES6')}}Initial definition in an ECMA standard. Specified that new is required.
{{SpecName('ESDraft', '#table-49', 'TypedArray constructors')}}{{Spec2('ESDraft')}}ECMAScript 2017 changed the Uint8Array constructor to use the ToIndex operation and allows constructors with no arguments.
+ +

Browser compatibility

+ + + +

{{Compat("javascript.builtins.Uint8Array")}}

+ +

Compatibility notes

+ +

Starting with ECMAScript 2015, Uint8Array constructors require to be constructed with a {{jsxref("Operators/new", "new")}} operator. Calling a Uint8Array constructor as a function without new, will throw a {{jsxref("TypeError")}} from now on.

+ +
var dv = Uint8Array([1, 2, 3]);
+// TypeError: calling a builtin Uint8Array constructor
+// without new is forbidden
+ +
var dv = new Uint8Array([1, 2, 3]);
+ +

See also

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