1, Literal measure

var obj = {
    name: 'mm',
    age: 18,
    sayName: function() {
        console.log(this.name);
    }
}

Problem: creating multiple objects can cause code redundancy and take up a lot of memory space.

2, Factory mode

function createToy(name) {
    var o = new Object();
    o.name = name;
    o.say = function() {
        console.log(this.name);
    }
    return o;
}
var toy1 = createToy('car');
toy1.say();
var toy2 = createToy('taxi');
toy2.say();
var toy3 = createToy('bus');
toy3.say();
console.log(toy1 instanceof Object);
console.log(toy2 instanceof Object);
console.log(toy3 instanceof Object);

Problem: Although the problem of creating object redundancy by object literal is solved, the problem of object recognition exists.

3, Constructor mode

function Toy(name) {
    this.name = name;
    this.say = function() {
        console.log(this.name);
    }
}
var toy1 = new Toy('car');
var toy2 = new Toy('car');
console.log(toy1.constructor);
console.log(toy2.constructor);
console.log(toy1.say === toy2.say); // false

Problem: solved the problem of factory mode, but the same method of repeated creation wasted memory space.

4, Prototype mode

function Person() {};
Person.prototype = {
    constructor: Person,
    name: 'mm',
    friends: ['mike','helen'],
    say: function() {
        console.log(this.name);
    }
}
var toy1 = new Person('train');
var toy2 = new Person('bus');
toy1.friends.push('suhai');
console.log(toy1.friends);
console.log(toy2.friends);

Problem: sharing method solves the problem of constructor. However, the properties of the reference type of the current instance are shared by all instances.

5, Combination mode (constructor + prototype mode)

function Person(name) {
    this.name = name;
    this.friends = ['mike','helen'];
};
Person.prototype = {
    constructor: Person,
    say: function() {
        console.log(this.name);
    }
}
var toy1 = new Person('train');
var toy2 = new Person('bus');
toy1.friends.push('suhai');
console.log(toy1.friends);
console.log(toy2.friends);

This is a common way to create.
The instance property is defined by constructor pattern, and the method and shared property are defined by prototype pattern.