Nice example of hoisting and how local foo() function definition is pushed to the top of the scope, while the definition of bar() is not hoisted. Only its declaration.

main.js

    function foo() {
        console.log('global foo');
    }
    function bar() {
        console.log('global bar');
    }
    function hoistMe() {
        console.log(typeof foo); // "function"
        console.log(typeof bar); // "undefined"

        foo(); // "local foo"
        bar(); // TypeError: undefined (bar) is not a function

        // Function declaration:
        // variable 'foo' and its implementation both get hoisted
        function foo() {
            console.log('local foo');
        }
        // Function expression:
        // only variable 'bar' gets hoisted, not the implementation
        var bar = function () {
            console.log('local bar');
        };
    }
    hoistMe();