gistfile1.js

var a = 1; 
    function b() { 
       a = 10; 
       return; 
       function a() {} 
    } 
   b(); 
   alert(a);
   
//Using the code above, the browser will alert "1".
//I'm still unsure why it returns "1". 


//Function hoisting means that functions are moved to the top of their scope. That is,

function b() {  
   a = 10;  
   return;  
   function a() {} 
} 
//will be rewritten by the interpeter to this

function b() {
  function a() {}
  a = 10;
  return;
}
//Weird, eh?

//Also, in this instance,

function a() {}
//behaved the same as

var a = function () {};
//So, in essence, this is what the code is doing:

var a = 1;                 //defines "a" in global scope
function b() {  
   var a = function () {}; //defines "a" in local scope 
   a = 10;                 //overwrites local variable "a"
   return;      
}       
b();       
alert(a);                 //alerts global variable "a"

js hoisting function declaration vs fn expression.js

function test() {
	foo(); // TypeError "foo is not a function"
	bar(); // "this will run!"
	var foo = function () { // function expression assigned to local variable 'foo'
		alert("this won't run!");
	}
	function bar() { // function declaration, given the name 'bar'
		alert("this will run!");
	}
}
test();

js hoisting.js

// both the functions are same
//http://www.adequatelygood.com/JavaScript-Scoping-and-Hoisting.html

function foo() {
	if (false) {
		var x = 1;
	}
	return;
	var y = 1;
}
function foo() {
	var x, y;
	if (false) {
		x = 1;
	}
	return;
	y = 1;
}