function scope closures implicit declaration

gistfile1.js

//these three are the same
function foo() {
    var wes = 'wes';
    var peter = 'peter';
}
function foo() {
    var wes, peter;

    wes = 'wes';
    peter = 'peter';
}
function foo(){
    var wes = 'wes',
        peter = 'peter';
}

//this is not
function foo(){
    wes = 'wes';
    peter = 'peter';
}
//those were created in the global scope (bad thing)

//closed variable manipulated in a function
function outerClosure(){
    var wes, peter;

    function innerFunction(){
        wes = 'wes';
        peter = 'peter';
    }
    innerFunction()
    return [wes, peter];
}
outerClosure(); //returns ['wes', 'peter']

function outerClosure(){
    var wes, peter;

    function innerFunction(){
        var wes = 'wes';
        var peter = 'peter';
    }
    innerFunction()
    return [wes, peter];
}
outerClosure(); //returns [undefined, undefined]