javascript 如何将类数组应用于 classList.contains？
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How to apply an array of classes to classList.contains?
提问by sdleihssirhc
In my HTML, I have a divlike so:
在我的 HTML 中，我有一个div像这样的：
<div class="a b c"></div>
In my JavaScript, I have an array of classes that I'm interested in:
在我的 JavaScript 中，我有一组我感兴趣的类：
var goodClasses = ['a', 'c'];
In good browsers, I can use the awesome classListfeature to test whether or not my divhas the appropriate classes:
在好的浏览器中，我可以使用 awesomeclassList功能来测试我的是否div有合适的类：
return div.classList.contains(goodClasses[0], goodClasses[1]);
This is okay, but what I'd really like to do is something like this (the syntax is silly, but this is the general idea):
这没关系，但我真正想做的是这样的事情（语法很愚蠢，但这是一般想法）：
return div.classList.contains.apply(div, goodClasses);
Is there some way to do this? If I have to loop through my array of classes anyway, classListbecomes a whole lot less cool.
有没有办法做到这一点？如果无论如何我必须循环遍历我的类数组，classList就会变得不那么酷了。
回答by user113716
As @Felix Klingcorrectly points out, classList.containsaccepts only one argument.
正如@Felix Kling正确指出的那样，classList.contains只接受一个参数。
If your supported browsers support the every()method on Array, you could do this:
如果您支持的浏览器支持 上的every()方法Array，您可以这样做：
return goodClasses.every( function( c ) {
return div.classList.contains( c );
});
Browsers that don't support it can use the MDC compatibility fix:
不支持它的浏览器可以使用MDC 兼容性修复：
if (!Array.prototype.every)
{
Array.prototype.every = function(fun /*, thisp */)
{
"use strict";
if (this === void 0 || this === null)
throw new TypeError();
var t = Object(this);
var len = t.length >>> 0;
if (typeof fun !== "function")
throw new TypeError();
var thisp = arguments[1];
for (var i = 0; i < len; i++)
{
if (i in t && !fun.call(thisp, t[i], i, t))
return false;
}
return true;
};
}
