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Inheritance

"Objects obtaining features from parent objects"

For example an Animal constructor may have a prototype "move", as all animals can move. When a new animal type is made it can inherit all the properties of Animal but then additional properties can be added. For example a dog can also bark and cat meow, but they both inherit the move prototype.

// Inheritance

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

Animal.prototype.move = function () {
    return true;
};

function Dog(name) {
  this.init(name);
}

Dog.prototype = new Animal();

Dog.prototype.bark = function () {
    return true;
};

function Cat(name) {
  this.init(name);
}

Cat.prototype = new Animal();

Cat.prototype.meow = function () {
    return true;
};

var bonnie = new Dog('bonnie', 12);
var minnie = new Cat('minnie', 5);

// true
console.log(bonnie.move());

// true
console.log(bonnie.bark());

// is not a function
console.log(bonnie.meow());

// true
console.log(minnie.meow());

Refs