Prototype

JavaScript

function Dog() {
};
Dog.prototype.bark = function() {
        console.log("Woof");
}
var snoopy = new Dog();
snoopy.bark();
// Woof

function Dog() {
    this.bark = function() {
        console.log("Woof");
    };
}
var snoopy = new Dog();
snoopy.bark();
// Woof