Method vs Functions, and other questions

Question

With respect to JS, what\'s the difference between the two? I know methods are associated with objects, but am confused what\'s the purpose of functions? How does the syntax

Answer 1

var myFirstFunc = function(param) {
    //Do something
};

and

function myFirstFunc(param) {
    //Do something
};

are (almost) identical. The second is (usually) just shorthand. However, as this jsfiddle (http://jsfiddle.net/cu2Sy/) shows, function myFirstFunc will cause the function to be defined as soon as the enclosing scope is entered, whereas myFirstFunc = function will only create it once execution reaches that line.

As for methods, they have a this argument, which is the current object, so:

var obj = {};
obj.func = function( ) {
    // here, "this" is obj
    this.test = 2;
}
console.log( obj.test ); // undefined
obj.func( );
console.log( obj.test ); // 2

The exact syntax you showed is because you can also do this:

function abc( ) {
    this.test = 2;
}
var obj = {};
obj.func = abc;
obj.func( ); // sets obj.test to 2

but you shouldn't without good reason.