Question

I’m looking for a simple example of creating a class in Javascript which is then inherited in a subclass. I’m looking in particular for an example of method overridding. I realize Javascript doesn’t have the syntax supporting traditional OOP, which seems to be the source of my problem.

Answer 1

Here is a simple example showing one of many ways of doing it. I usually use John Resig’s system.

function Animal(name) {
    this.name = name;
}

Animal.prototype.eat = function() {
    alert(this.name + " is eating");
};

Animal.prototype.speak = function() {
    alert("Hi my name is " + this.name);
};


function Cow(name) {
    this.name = name;
}
Cow.prototype = new Animal();

Cow.prototype.speak = function() {
    alert("Moooo");
};



var a = new Animal("John");
a.eat();
a.speak();

var c = new Cow("Mary");
c.eat();
c.speak();

http://jsfiddle.net/Xeon06/JK5vX/2/