How can I get the name of function inside a JavaScript function?

I think that you can do that :

var name = arguments.callee.toString();

For more information on this, take a look at this article.

function callTaker(a,b,c,d,e){
  // arguments properties
  console.log(arguments);
  console.log(arguments.length);
  console.log(arguments.callee);
  console.log(arguments[1]);
  // Function properties
 console.log(callTaker.length);
  console.log(callTaker.caller);
  console.log(arguments.callee.caller);
  console.log(arguments.callee.caller.caller);
  console.log(callTaker.name);
  console.log(callTaker.constructor);
}

function callMaker(){
  callTaker("foo","bar",this,document);
}

function init(){
  callMaker();
}

This will work:

function test() {
  var z = arguments.callee.name;
  console.log(z);
}