jQuery's reliable method to determine whether an element exists_jquery

The simplest way is to determine the matching length of the element

For example, HTML code:

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Usually our approach is

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if($('.mydiv ').length>0)

The more reliable and error-free method is:

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if($('.mydiv').length && $('.mydiv').length>0)
return true;

Use the traditional javascript method, as follows:

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if( document.getElementById('div')) {                                                    
Using jQuery is relatively simple. You only need to determine whether the length of this element is 0. If it is 0, this element does not exist. The code is as follows:

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The code is as follows: if ($("#div").length > 0){ // Find the element corresponding to id=div, and then Executing this block of code }

can even find the combined element. As follows, we find whether an element whose id is defined as div contains img. The code is as follows:

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The code is as follows:if ($("#div img").length > 0){ // found Correspond to the element with id=div and contain img, and then execute this block of code }

Isn’t it very simple? You can try it