contains()
方法在
DOMTokenList
interface returns a
布尔
—
true
if the underlying list contains the given
token
,否则
false
.
tokenList.contains(token);
token
DOMString
representing the token you want to check for the existance of in the list.
A
布尔
,其是
true
if the calling list contains
token
,否则
false
.
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 | 状态 | 注释 |
|---|---|---|
|
DOM
The definition of 'contains()' in that specification. |
实时标准 | 初始定义 |
| 桌面 | 移动 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
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 |
完整支持
DOMTokenList
AbortController
AbortSignal
AbstractRange
Attr
ByteString
CDATASection
CSSPrimitiveValue
CSSValue
CSSValueList
CharacterData
ChildNode
注释
CustomEvent
DOMConfiguration
DOMError
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DOMException
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DOMImplementationList
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DOMImplementationSource
DOMLocator
DOMObject
DOMParser
DOMPoint
DOMPointInit
DOMPointReadOnly
DOMRect
DOMString
DOMTimeStamp
DOMUserData
Document
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DocumentType
元素
ElementTraversal
Entity
EntityReference
事件
EventTarget
HTMLCollection
MutationObserver
节点
NodeFilter
NodeIterator
NodeList
NonDocumentTypeChildNode
ProcessingInstruction
PromiseResolver
范围
StaticRange
文本
TextDecoder
TextEncoder
TimeRanges
TreeWalker
TypeInfo
USVString
UserDataHandler
XMLDocument