Javascript inheritence

prototypal-inheritence

{
    "name": "Inheritence",
    "cells": [
        {
            "in": "// prototypal inheritence\n// http://oli.me.uk/2013/06/01/prototypical-inheritance-done-right/\n",
            "out": "3"
        },
        {
            "in": "function Vehicle(name){\n\tthis.name = name;\n}\n\nVehicle.prototype.getName = function(){\n\treturn this.name;\n}\n\nvar veh1 = new Vehicle('lorry');\nconsole.log(veh1.getName())\n",
            "out": "lorry\nundefined"
        },
        {
            "in": "function car(){}\n\ncar.prototype = Vehicle.prototype;\ncar.prototype.colour = \"none\";\ncar.prototype.setColour = function(colour){\n\tthis.color = colour;\n}\n\nveh1.colour;",
            "out": "'none'"
        },
        {
            "in": "// observe the prorotype of vehicle is changed & hence even veh1 got the property colour\n// but we only wanted the colour property for the car objects\n\n// we can overcome this problem by using Object.create",
            "out": ""
        },
        {
            "in": "function Vehicle(name){\n\tthis.name = name;\n}\n\nVehicle.prototype.getName = function(){\n\treturn this.name;\n}\n\nvar veh1 = new Vehicle('lorry');\nconsole.log(veh1.getName())\n\nfunction Car(){}\n\n// use Object.create to copy prototype\nCar.prototype = Object.create(Vehicle.prototype);\nCar.prototype.colour = \"none\";\nCar.prototype.setColour = function(colour){\n\tthis.colour = colour;\n}\n\nveh1.colour;",
            "out": "lorry\nundefined"
        },
        {
            "in": "var car1 = new Car(\"Benz\");\ncar1.setColour(\"black\");\ncar1.colour",
            "out": "'black'"
        },
        {
            "in": "// one more problem !\nveh1.constructor;\n",
            "out": "[Function: Vehicle]"
        },
        {
            "in": "car1.constructor;",
            "out": "[Function: Vehicle]"
        },
        {
            "in": "// wtf!!!",
            "out": ""
        },
        {
            "in": "function Vehicle(name){\n\tthis.name = name;\n}\n\nVehicle.prototype.getName = function(){\n\treturn this.name;\n}\n\nvar veh1 = new Vehicle('lorry');\n\n\nfunction Car(){}\n\n// use Object.create to copy prototype\nCar.prototype = Object.create(Vehicle.prototype);\nCar.prototype.constructor = Car;\nCar.prototype.colour = \"none\";\nCar.prototype.setColour = function(colour){\n\tthis.colour = colour;\n}\n\n",
            "out": "[Function]"
        },
        {
            "in": "var car1 = new Car(\"Benz\");\ncar1.setColour(\"black\");\ncar1.colour",
            "out": "'black'"
        },
        {
            "in": "veh1.constructor;",
            "out": "[Function: Vehicle]"
        },
        {
            "in": "car1.constructor;",
            "out": "[Function: Car]"
        },
        {
            "in": "veh1 instanceof Vehicle;",
            "out": "true"
        },
        {
            "in": "car1 instanceof Vehicle;",
            "out": "true"
        },
        {
            "in": "// how to use methods from base prototype when we override?",
            "out": ""
        },
        {
            "in": "function Vehicle(name){\n\tthis.name = name;\n}\n\nVehicle.prototype.getName = function(){\n\treturn this.name;\n}\n\nvar veh1 = new Vehicle('lorry');\n\n\nfunction Car(name){\n\tVehicle.call(this, name);\n}\n\n// use Object.create to copy prototype\nCar.prototype = Object.create(Vehicle.prototype);\nCar.prototype.constructor = Car;\nCar.prototype.colour = \"none\";\nCar.prototype.setColour = function(colour){\n\tthis.colour = colour;\n}\n\nCar.prototype.getName = function(){\n\tvar baseRes = Vehicle.prototype.getName.call(this);\n\treturn \"Car is \"+baseRes;\n}\n",
            "out": "[Function]"
        },
        {
            "in": "var car2 = new Car(\"BMW\");\nconsole.log(car2.getName())",
            "out": "Car is BMW\nundefined"
        },
        {
            "in": "car2 instanceof Vehicle;",
            "out": "true"
        }
    ]
}