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diff --git a/files/he/web/javascript/reference/statements/const/index.html b/files/he/web/javascript/reference/statements/const/index.html deleted file mode 100644 index 98de11967b..0000000000 --- a/files/he/web/javascript/reference/statements/const/index.html +++ /dev/null @@ -1,133 +0,0 @@ ---- -title: const -slug: Web/JavaScript/Reference/Statements/const -tags: - - const - - מה זה const - - משתנים -translation_of: Web/JavaScript/Reference/Statements/const ---- -<div>{{jsSidebar("Statements")}}</div> - -<div>מילת ההצהרה <strong><code>const</code></strong> משמשת להכזרה על משתנה קבוע שאין אפשרות לשנות את הערך שלו.<br> - </div> - -<div>{{EmbedInteractiveExample("pages/js/statement-const.html")}}</div> - - - -<h2 id="תחביר">תחביר</h2> - -<pre class="syntaxbox">const <em>name1 = <em>value1 [</em>, <em>name2</em> = <em>value2</em><em> [</em>, ... [</em>, <em>nameN</em> = <em>valueN]]]</em>;</pre> - -<dl> - <dt><code>nameN</code></dt> - <dd>שם המשתנה.</dd> - <dt><code>valueN</code></dt> - <dd>הערך של המשתנה.</dd> -</dl> - -<h2 id="תיאור">תיאור</h2> - -<p>בשפת ג'אווה סקריפט אנו משתמשים במשתנים על מנת להחזיק ערכים שונים.<br> - הצהרה על משתנה באמצעות <strong><code>const</code></strong> הופכת אותו לקבוע ולא ניתן לשנות את הערך שלו.<br> - הקצאת ערך למשתנה ללא הצהרה מראש הופכת אותו למשתנה גלובלי, אך בשונה מהצהרה באמצעות <strong><code>var</code></strong> הוא אינו כפוף לאובייקט האב <strong><code>window</code></strong>.<br> - חשוב לציין שהצהרה באמצעות const לא מבצעת <a href="/he/docs/">Hoisting</a>.</p> - -<h2 id="דוגמאות">דוגמאות</h2> - -<p>הדוגמה הבאה ממחישה כיצד מתנהגים משתנים קבועים.</p> - -<pre class="brush:js">// NOTE: Constants can be declared with uppercase or lowercase, but a common -// convention is to use all-uppercase letters. - -// define MY_FAV as a constant and give it the value 7 -const MY_FAV = 7; - -// this will throw an error - Uncaught TypeError: Assignment to constant variable. -MY_FAV = 20; - -// MY_FAV is 7 -console.log('my favorite number is: ' + MY_FAV); - -// trying to redeclare a constant throws an error - Uncaught SyntaxError: Identifier 'MY_FAV' has already been declared -const MY_FAV = 20; - -// the name MY_FAV is reserved for constant above, so this will fail too -var MY_FAV = 20; - -// this throws an error too -let MY_FAV = 20; - -// it's important to note the nature of block scoping -if (MY_FAV === 7) { - // this is fine and creates a block scoped MY_FAV variable - // (works equally well with let to declare a block scoped non const variable) - let MY_FAV = 20; - - // MY_FAV is now 20 - console.log('my favorite number is ' + MY_FAV); - - // this gets hoisted into the global context and throws an error - var MY_FAV = 20; -} - -// MY_FAV is still 7 -console.log('my favorite number is ' + MY_FAV); - -// throws an error - Uncaught SyntaxError: Missing initializer in const declaration -const FOO; - -// const also works on objects -const MY_OBJECT = {'key': 'value'}; - -// Attempting to overwrite the object throws an error - Uncaught TypeError: Assignment to constant variable. -MY_OBJECT = {'OTHER_KEY': 'value'}; - -// However, object keys are not protected, -// so the following statement is executed without problem -MY_OBJECT.key = 'otherValue'; // Use Object.freeze() to make object immutable - -// The same applies to arrays -const MY_ARRAY = []; -// It's possible to push items into the array -MY_ARRAY.push('A'); // ["A"] -// However, assigning a new array to the variable throws an error - Uncaught TypeError: Assignment to constant variable. -MY_ARRAY = ['B'];</pre> - -<h2 id="מפרט">מפרט</h2> - -<table class="standard-table"> - <thead> - <tr> - <th scope="col">Specification</th> - <th scope="col">Status</th> - <th scope="col">Comment</th> - </tr> - </thead> - <tbody> - <tr> - <td>{{SpecName('ES2015', '#sec-let-and-const-declarations', 'Let and Const Declarations')}}</td> - <td>{{Spec2('ES2015')}}</td> - <td>Initial definition.</td> - </tr> - <tr> - <td>{{SpecName('ESDraft', '#sec-let-and-const-declarations', 'Let and Const Declarations')}}</td> - <td>{{Spec2('ESDraft')}}</td> - <td>No changes.</td> - </tr> - </tbody> -</table> - -<h2 id="תאימות_דפדפן">תאימות דפדפן</h2> - - - -<p>{{Compat("javascript.statements.const")}}</p> - -<h2 id="ראה_גם">ראה גם</h2> - -<ul> - <li><a href="https://developer.mozilla.org/he/docs/Web/JavaScript/Reference/Statements/var"><code>var</code></a></li> - <li><a href="https://developer.mozilla.org/he/docs/Web/JavaScript/Reference/Statements/let"><code>let</code></a></li> -</ul> |