do...while 语句创建一个执行指定语句的循环,直到condition值为 false。在执行statement 后检测condition,所以指定的statement至少执行一次。

语法

do
   statement
while (condition);
statement
执行至少一次的语句,并在每次 condition 值为真时重新执行。想执行多行语句,可使用block语句{ ... }包裹这些语句。
condition
循环中每次都会计算的表达式。如果 condition 值为真, statement 会再次执行。当 condition 值为假,则跳到do...while之后的语句。

示例

使用 do...while

下面的例子中,do...while 循环至少迭代一次,并且继续迭代直到 i不再小于 5 时结束。

HTML 内容

<div id="example"></div>

JavaScript 内容

var result = '';
var i = 0;
do {
   i += 1;
   result += i + ' ';
} while (i < 5);
document.getElementById('example').innerHTML = result;

结果

规范

Specification Status Comment
ECMAScript 3rd Edition (ECMA-262) Standard Initial definition. Implemented in JavaScript 1.2
ECMAScript 5.1 (ECMA-262)
do-while statement
Standard  
ECMAScript 2015 (6th Edition, ECMA-262)
do-while statement
Standard Trailing ; is now optional.
ECMAScript Latest Draft (ECMA-262)
do-while statement
Draft  

浏览器兼容

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung InternetNode.js
Basic supportChrome Full support YesEdge Full support YesFirefox Full support 1IE Full support 6Opera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yesnodejs Full support Yes

Legend

Full support  
Full support

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此页面的贡献者: zhangchen, yenshen
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