How can I insert a script into HTML head dynamically using JavaScript? [duplicate]

Question

How can I insert a script into HTML head dynamically using JavaScript?

Answer 1

var head = document.getElementsByTagName('head')[0]; var script = document.createElement('script'); script.type = 'text/javascript'; script.onload = function() {     callFunctionFromScript(); } script.src = 'path/to/your-script.js'; head.appendChild(script); 

Answer 2

Here is how I injected a function on the fly without any source file, etc.

document.head.appendChild(document.createElement('script').text = 'function LogIt(msg) { console.log(msg);}' ); 

And to inject to body

document.body.appendChild(document.createElement('script').text = 'function LogIt(msg) { console.log(msg);}' ); 

After executing this, if you try LogIt('hello');, you should see 'hello' in the console.