[英]what's the meaning of the function?
function hasClass( elem, cls ) {
var reClass = new RegExp(' ' + cls + ' ');
return reClass.test(' ' + elem.className + ' ');
}
i am a new learner of javascript, i saw the above function from a book.but i don't what's the meaning of it? 我是javascript的新手,我从一本书中看到了上述功能。但是我不知道它的含义是什么? expect someone can explain it to me.many thanks.
希望有人可以向我解释。非常感谢。
It's just testing whether a given element contains a given class. 它只是测试给定元素是否包含给定类。 This is useful for elements with multiple classes (older browsers don't support that by default).
这对于具有多个类的元素很有用(默认情况下,旧版浏览器不支持该类)。
Consider an element like <div id='test' class="button login"></div>
. 考虑类似
<div id='test' class="button login"></div>
的元素。 If you pass that to the function, you'll get as follows: 如果将其传递给函数,将得到如下结果:
function hasClass( elem, cls ) {
// var reClass = new RegExp(' login ');
var reClass = new RegExp(' ' + cls + ' ');
// return reClass.test(' button login '); (ie, true)
return reClass.test(' ' + elem.className + ' ');
}
console.log(hasClass(document.getElementById('test'), 'login'));
它检查元素的class属性是否包含指定的类(cls)
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