How do you check if a selector matches something in jQuery?

2018-06-04 12:15:42

This question already has an answer here:

Is there an “exists” function for jQuery? 36 answers

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

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

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

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

Then in your code you can use

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

As answered here

no, jquery always returns a jquery object regardless if a selector was matched or not. You need to use .length

if ( $('#someDiv').length ){

}

if you used:

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

you would imply that chaining was possible when it is not.

This would be better

jQuery.exists = function(selector) {return ($(selector).length > 0);}
if ($.exists(selector)) { }

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