JavaScript Scoping and Hoisting

javascript_scoping_and_hoisting.js

// related write-up
//     http://www.adequatelygood.com/JavaScript-Scoping-and-Hoisting.html

// example code

var a = 1;

function b (arguments) {
    var a = 3;

    console.log (a);
    console.log (arguments);

    return;

    function a () {}
}

b (2);

console.log (a);

// output

/*
3
2
1
*/

// what the code looks like after "hoisting"

function b (arguments) {
    function a () {}
  
    var a; // no effect, this declartation doesn't override an existing property.

    a = 3; // the function is gone at this point.

    console.log (a);
    console.log (arguments);

    return;
}

var a;

a = 1;
b (2);

console.log (a);

// output

/*
3
2
1
*/