Func declaration vs Func expressin.js

// 1.
function foo(){
   function bar() {return 3;}
   return bar();
   function bar() {return 8;}
}
alert(foo()); // 8

// mais
// 2. 
function foo(){
    var bar = function() {return 3;};
    return bar();
    var bar = function() {return 8;};
}
alert(foo()); // 3

/*

   1. Using Function Declaration
      - visible outside of it’s scope
      - “Function declarations and function variables are always moved (‘hoisted’) to the top of their JavaScript scope by the JavaScript interpreter”
   2. Using Function Expression
      - not visible outside of it’s scope
      
   Read more: <http://javascriptweblog.wordpress.com/2010/07/06/function-declarations-vs-function-expressions/>
   
*/