Javascript does not have class object, what it has to allow Inheritance is prototype object, which is just another object. The way to create an new object from a prototype object is to define a constructor function for the new object and decorate the prototype property( which is an object) of the constructor function( which is also object in jav…

Create a new object from prototype.js

// 1. define a constructor function for the new object:
var objectConstructor = function(){
    this.objAttr = "objAttr";
    this.objMethod = function(){
        alert("obj method");
    }
}

// 2. decorate the prototype property of the constructor function
objectConstructor.prototype.protoAttr = "protoAttr";
objectConstructor.prototype.protoMethod = function(){
    alert("proto method");
}

// 3. initiate the new object
object = new objectConstructor();


alert(object.objAttr);
object.objMethod();
alert(object.protoAttr);
object.protoMethod();

prototype-based object inheritance.js

// 1. create an parent object from prototype
var parentObjConstructor = function(){
   this.parentObjAttr = "parentObjAttr";
};

parentObjConstructor.prototype.parentProtoAttr = "parentProtoAttr";


// 2. create child object which inherit from the parent object
// 2.1 create a constructor function for the child object
var childObjConstructor = function(){
   this.childObjAttr = "childObjAttr";
};

// 2.2 assign the parent object to the child object's prototype property
childObjConstructor.prototype = new parentObjConstructor();

// 2.3 decorate the prototype property to extend the parent prototype
childObjConstructor.prototype.childProtoAttr = "childProtoAttr";

// 2.4 initiate the new object
var childObj = new childObjConstructor();


alert(childObj.parentObjAttr);
alert(childObj.parentProtoAttr);
alert(childObj.childObjAttr);
alert(childObj.childProtoAttr);