How Do I Add jQuery To Head With JavaScript?

Question

I am trying to include jQuery to an HTML page conditionally. It only needs to be added if it doesn\'t exist yet.

I am using the following code near the top of my bod

Answer 1

You are not waiting for the script to load after appending it to document

Try this code before appending:

   function helper(){
        if (typeof jQuery === 'undefined') {
            alert('jquery still not present :(');
        }
   };

   script.onreadystatechange= function () {
      if (this.readyState == 'complete') helper();
   }
   script.onload= helper;

I've found it here if you want to know more

Also there are loaders like StealJS or YepNope