javascript - 你如何检查选择器是否匹配jQuery中的内容？ [重复](How do you check if a selector matches something in jQuery? [duplicate])

Question

This question already has an answer here:

(这个问题在这里已有答案：)

• Is there an “exists” function for jQuery?

  (jQuery是否存在“存在”功能？)

  40 answers

  (40个答案)

In Mootools, I'd just run if ($('target')) { ... } .

(在Mootools中，我只运行if ($('target')) { ... } 。)

Does if ($('#target')) { ... } in jQuery work the same way?

(if ($('#target')) { ... } jQuery中的if ($('#target')) { ... }以相同的方式工作吗？)

  ask by One Crayon translate from so

Answer 1

As the other commenters are suggesting the most efficient way to do it seems to be:

(正如其他评论者所建议的那样，最有效的方法似乎是：)

if ($(selector).length ) {
    // Do something
}

If you absolutely must have an exists() function - which will be slower- you can do:

(如果你绝对必须有一个exists（）函数 - 它会更慢 - 你可以这样做：)

jQuery.fn.exists = function(){return this.length>0;}

Then in your code you can use

(然后在你的代码中你可以使用)

if ($(selector).exists()) {
    // Do something
}

As answered here

(在这里回答)