Type error: undefined is not a function

Question

I get this error on line below. How to solve this??

jQuery('span.facebookbtn, .fb-like-box').exists(function() {
        load('//connect.facebook.net/en_US/all.js#xfbml=1', 'fbjssdk'); 
}

Answer 1

Assuming you want to load the data if the element exists on the page:

Jquery has no "exists" function. Instead we use ".length".

Example:

if (jQuery('span.facebookbtn, .fb-like-box').length)
    load('//connect.facebook.net/en_US/all.js#xfbml=1', 'fbjssdk'); 

Answer 2

Do you have defined exists function? I am not aware that it's a built in function,

Perhaps you should use length functuion instead:

if (jQuery('span.facebookbtn, .fb-like-box').length){
        load('//connect.facebook.net/en_US/all.js#xfbml=1', 'fbjssdk'); 
}

Answer 3

There is no exists() function in jQuery (see this question), you either have to define it first (jQuery.fn.exists = function(){return this.length>0;}) or use the length property directly for checking the existence of an element as suggested by the jQuery documentation.