create

File Location

We will be working in the following file:

    javascript-library
        └── 0-PreWork
        └── 1-Fundamentals
            └── 11-Objects
                01-properties.js
                02-enumeration.js
                03-initializers.js 
                04-constructor-function.js 
                05-create.js <----You will be working in this file.

Object.create() is a built-in method that allows you to create a new instance of an object from a currently-existing object. It allows you to make multiple objects with the same properties without having to make a constructor function first. After it has been created, you can assign new values to the properties if you want to.

Object.create

We can use .create to make a new person without having to use a constructor:

var paul = {
    name: "Paul",
    age: 41
};

var sophie = Object.create(paul);
var ava = Object.create(paul);

This process can be time-consuming, especially if the object has several properties that need to be changed. See what happens if we use the original Person object:

let Aaron = {
    age: 30,
    height: '70in',
    hairColor: 'brown',
    eyeColor: 'black',
    glasses: true
};

let Kaylea = Object.create(Aaron);

//Object Kaylea has the same properties of object Aaron, so we have to maually change each property
Kaylea.age = 26;
Kaylea.height = "66in";
Kaylea.hairColor = 'black';
Kaylea.eyeColor = "brown";
Kaylea.glasses = false;

Imagine having to make a person object for everyone in the class this way. Now imagine if there were 10 properties instead of 5, and that you have 500 users a day each making a person object. You can see how much extra time this takes. If the object you are creating has a small number of properties, or the property values will be the same as the original, the create method can be very useful. If there are more than a couple of properties or there are a large number of objects to be created, however, it will generally be easier to use a constructor function.

Practice

1. Make a new object, then use Object.create() to create copies of it.

2. Come up with some situations where the create method would be easier to use than the constructor function.