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The do...while
statement creates a loop that executes a specified statement until the test condition evaluates to false. The condition is evaluated after executing the statement, resulting in the specified statement executing at least once.
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Syntax
do statement while (condition);
statement
- A statement that is executed at least once and is re-executed each time the condition evaluates to true. To execute multiple statements within the loop, use a
block
statement ({ ... }
) to group those statements.
condition
- An expression evaluated after each pass through the loop. If
condition
evaluates to true, thestatement
is re-executed. Whencondition
evaluates to false, control passes to the statement following thedo...while
.
Examples
Using do...while
In the following example, the do...while
loop iterates at least once and reiterates until i
is no longer less than 5.
HTML content
<div id="example"></div>
JavaScript content
var result = ''; var i = 0; do { i += 1; result += i + ' '; } while (i < 5); document.getElementById('example').innerHTML = result;
Result
Specifications
Specification | Status | Comment |
---|---|---|
ECMAScript 3rd Edition (ECMA-262) | Standard | Initial definition. Implemented in JavaScript 1.2 |
ECMAScript 5.1 (ECMA-262) The definition of 'do-while statement' in that specification. |
Standard | |
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'do-while statement' in that specification. |
Standard | Trailing ; is now optional. |
ECMAScript Latest Draft (ECMA-262) The definition of 'do-while statement' in that specification. |
Draft |
Browser compatibility
Desktop | Mobile | Server | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Basic support | Chrome Full support Yes | Edge Full support Yes | Firefox Full support 1 | IE Full support 6 | Opera Full support Yes | Safari Full support Yes | WebView Android Full support Yes | Chrome Android Full support Yes | Edge Mobile Full support Yes | Firefox Android Full support 4 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support Yes | nodejs Full support Yes |
Legend
- Full support
- Full support