Adding methods to a class vs adding methods to a class's prototype

https://www.quora.com/JavaScript/What-are-advantages-to-adding-methods-to-a-class-vs-adding-methods-to-a-classs-prototype

Snippet 1 (Adding methods to a class)

var myClass = function(prop1, prop2) {

    this.prop1 = prop1;

    this.prop2 = prop2;

    this.method1 = function() {//blah}

    this.method2 = function() {//blahblah}

}

Snippet 2 (Adding methods to a class's prototype)

var myClass = function(prop1, prop2) {

    this.prop1 = prop1;

    this.prop2 = prop2;

}

myClass.prototype.method1 = function() {//blah}

myClass.prototype.method2 = function() {//blahblah}

Snippet 1

• Two functions are created for every construction of 

  myClass

• can give you access to private variables and constructor arguments

Snippet 2

• the two functions are created once: when the prototype is filled.
• gives better memory usage
• Methods that inherit via the prototype chain can be changed universally for all instances
• For instance, you can extend the built-in String object by adding a trim function to it and all future instance of that object will share the trim function.

http://stackoverflow.com/questions/4508313/advantages-of-using-prototype-vs-defining-methods-straight-in-the-constructor