contains() 方法在 DOMTokenList interface returns a 布尔 true if the underlying list contains the given token ,否则 false .

句法

tokenList.contains(token);
					

参数

token
DOMString representing the token you want to check for the existance of in the list.

返回值

A 布尔 ,其是 true if the calling list contains token ,否则 false .

范例

In the following example we retrieve the list of classes set on a <span> element as a DOMTokenList 使用 Element.classList . We then test for the existence of "c" in the list, and write the result into the <span> 's Node.textContent .

First, the HTML:

<span class="a b c"></span>
					

Now the JavaScript:

let span = document.querySelector("span");
let classes = span.classList;
let result = classes.contains("c");
if (result) {
  span.textContent = "The classList contains 'c'";
} else {
   span.textContent = "The classList does not contain 'c'";
}
					

输出看起来像这样:

规范

规范 状态 注释
DOM
The definition of 'contains()' in that specification.
实时标准 初始定义

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据
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Chrome Edge Firefox Internet Explorer Opera Safari Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
包含 Chrome 1 Edge 12 Firefox Yes IE 10 Opera Yes Safari 5.1 WebView Android Yes Chrome Android Yes Firefox Android Yes Opera Android Yes Safari iOS 5.1 Samsung Internet Android Yes

图例

完整支持

完整支持

元数据

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