This is the 18th day of my participation in Gwen Challenge

Related articles:

• The prototype
• new
• inheritance

The prototype pattern

A prototype pattern is called a pattern in which an object is created by cloning a template based on an existing object. We can think of the stereotype pattern as based on prototype inheritance, where we create objects as prototypes for other objects. The prototype object itself is effectively used as a blueprint for each object created by the constructor.

True prototype inheritance, as defined in the ECMAScript 5 standard, requires the use of Object.create. To remind ourselves that the Object. The create create a Object with specified prototype, and can also contain the specified properties (such as the Object. The create (prototype, optionalDescriptorObjects)).

var myCar = {
 
  name: "Ford Escort".drive: function () {
    console.log( "Weeee. I'm driving!" );
  },
 
  panic: function () {
    console.log( "Wait. How do you stop this thing?"); }};// Use Object.create to instantiate a new car
var yourCar = Object.create( myCar );
 
// Now we can see that one is a prototype of the other
console.log( yourCar.name );
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Object.create also makes it easy to implement advanced concepts such as differential inheritance, where objects can be inherited directly from other objects. As we saw earlier, object.create allows us to initialize Object properties with the second supplied argument. Such as:

var vehicle = {
  getModel: function () {
    console.log( "The model of this vehicle is.." + this.model ); }};var car = Object.create(vehicle, {
 
  "id": {
    value: MY_GLOBAL.nextId(),
    // writable:false, configurable:false by default
    enumerable: true
  },
 
  "model": {
    value: "Ford".enumerable: true}});Copy the code

If we wish not to use the prototype pattern Object.create directly, we can emulate the pattern as shown in the above example:

var vehiclePrototype = {
 
  init: function ( carModel ) {
    this.model = carModel;
  },
 
  getModel: function () {
    console.log( "The model of this vehicle is.." + this.model); }};function vehicle( model ) {
 
  function F() {};
  F.prototype = vehiclePrototype;
 
  var f = new F();
 
  f.init( model );
  return f;
 
}
 
var car = vehicle( "Ford Escort" );
car.getModel();
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A final alternative implementation of the Prototype pattern might look like this:

var beget = (function () {
 
    function F() {}
 
    return function ( proto ) {
        F.prototype = proto;
        return newF(); }; }) ();Copy the code