var result = (function() {

    var x = 1;

​

    return (function () {

        return x;

​

        // this x gets hoisted to the top of the function,

        // and never gets initialized because it's after the return.

        var x = 2;

    })();

​

})();

​

console.log(result); // undefined

​

​

// Demonstartion of what happens at runtime:

var result = (function() {

    var x = 1;

​

    return (function () {

        var x;

        console.log(x); // undefined

        return x;

    })();

​

})();

​

console.log(result); // undefined