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Revision 33123 of let

  • Revision slug: JavaScript/Reference/Statements/let
  • Revision title: let
  • Revision id: 33123
  • Created:
  • Creator: tehsis
  • Is current revision? No
  • Comment 32 words added, 5 words removed

Revision Content

{{ Non-standard_header() }}{{ stub() }} {{ js_minversion_header("1.7") }}

Summary

Declares a local variable, optionally initializing it to a value.

Syntax

let definition:

let var1 [= value1] [, var2 [= value2]] [, ..., varN [= valueN]];

let expression:

let (var1 [= value1] [, var2 [= value2]] [, ..., varN [= valueN]]) expression;

let statement:

let (var1 [= value1] [, var2 [= value2]] [, ..., varN [= valueN]]) statement;

Parameters

Parameter Description
var1, var2, …, varN Variable name. It can be any legal identifier.
value1, value2, …, valueN Initial value of the variable. It can be any legal expression.
expression Any legal expression.
statement Any legal statement.

Description

Let allows to declare variables limiting its scope to an expression or a block, depending the way it is used.

When using inside a block its scope is that block.

Examples

See New in JavaScript 1.7.

See also

{{ languages( { "ja": "ja/JavaScript/Reference/Statements/let"} ) }}

Revision Source

{{ Non-standard_header() }}{{ stub() }} {{ js_minversion_header("1.7") }}
<h2>Summary</h2>
<p>Declares a local variable, optionally initializing it to a value.</p>
<h2>Syntax</h2>
<p><code>let</code> definition:</p>
<pre class="brush: js">let var1 [= value1] [, var2 [= value2]] [, ..., varN [= valueN]];
</pre>
<p><code>let</code> expression:</p>
<pre class="brush: js">let (var1 [= value1] [, var2 [= value2]] [, ..., varN [= valueN]]) expression;
</pre>
<p><code>let</code> statement:</p>
<pre class="brush: js">let (var1 [= value1] [, var2 [= value2]] [, ..., varN [= valueN]]) statement;
</pre>
<h2>Parameters</h2>
<table class="standard-table" style=""> <thead> <tr> <th scope="col">Parameter</th> <th scope="col">Description</th> </tr> </thead> <tbody> <tr> <td><code>var1</code>, <code>var2</code>, …, <code>varN</code></td> <td>Variable name. It can be any legal identifier.</td> </tr> <tr> <td><code>value1</code>, <code>value2</code>, …, <code>valueN</code></td> <td>Initial value of the variable. It can be any legal expression.</td> </tr> <tr> <td><code>expression</code></td> <td>Any legal <a href="/en/JavaScript/Guide/Expressions_and_Operators#Expressions" title="en/JavaScript/Guide/Expressions and Operators#Expressions">expression</a>.</td> </tr> <tr> <td><code>statement</code></td> <td>Any legal <a href="/en/JavaScript/Reference/Statements" title="en/JavaScript/Reference/Statements">statement</a>.</td> </tr> </tbody>
</table>
<h2>Description</h2>
<p>Let allows to declare variables limiting its scope to an expression or a block, depending the way it is used.</p>
<p>When using inside a block its scope is that block.</p>
<h2>Examples</h2>
<p>See <a href="/en/JavaScript/New_in_JavaScript/1.7#Block_scope_with_let_(Merge_into_let_Statement)" title="en/JavaScript/New in JavaScript/1.7#Block scope with let (Merge into let Statement)">New in JavaScript 1.7</a>.</p>
<h2>See also</h2>
<ul> <li><a href="/en/JavaScript/Reference/Statements/var" title="en/JavaScript/Reference/Statements/var"><code>var</code></a></li> <li><a href="/en/JavaScript/Reference/Statements/const" title="en/JavaScript/Reference/Statements/const"><code>const</code></a></li> <li><a href="/en/JavaScript/New_in_JavaScript/1.7#Block_scope_with_let_(Merge_into_let_Statement)" title="en/JavaScript/New in JavaScript/1.7#Block scope with let (Merge into let Statement)">New in JavaScript 1.7</a></li>
</ul>
<p>{{ languages( { "ja": "ja/JavaScript/Reference/Statements/let"} ) }}</p>
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