[javascript] Using "Object.create" instead of "new"

new Operator

  • This is used to create object from a constructor function
  • The new keywords also executes the constructor function
function Car() {
  console.log(this) // this points to myCar
  this.name = "Honda";
}

var myCar = new Car()
console.log(myCar) // Car {name: "Honda", constructor: Object}
console.log(myCar.name) // Honda
console.log(myCar instanceof Car) // true
console.log(myCar.constructor) // function Car() {}
console.log(myCar.constructor === Car) // true
console.log(typeof myCar) // object

Object.create

  • You can also use Object.create to create a new object
  • But, it does not execute the constructor function
  • Object.create is used to create an object from another object
const Car = {
  name: "Honda"
}

var myCar = Object.create(Car)
console.log(myCar) // Object {}
console.log(myCar.name) // Honda
console.log(myCar instanceof Car) // ERROR
console.log(myCar.constructor) // Anonymous function object
console.log(myCar.constructor === Car) // false
console.log(typeof myCar) // object

Examples related to javascript

need to add a class to an element How to make a variable accessible outside a function? Hide Signs that Meteor.js was Used How to create a showdown.js markdown extension Please help me convert this script to a simple image slider Highlight Anchor Links when user manually scrolls? Summing radio input values How to execute an action before close metro app WinJS javascript, for loop defines a dynamic variable name Getting all files in directory with ajax

Examples related to constructor

Two constructors Class constructor type in typescript? ReactJS: Warning: setState(...): Cannot update during an existing state transition Inheritance with base class constructor with parameters What is the difference between using constructor vs getInitialState in React / React Native? Getting error: ISO C++ forbids declaration of with no type undefined reference to 'vtable for class' constructor Call asynchronous method in constructor? Purpose of a constructor in Java? __init__() missing 1 required positional argument

Examples related to new-operator

Java FileOutputStream Create File if not exists How to add to an existing hash in Ruby Expression must have class type Why should C++ programmers minimize use of 'new'? Creating an object: with or without `new` int *array = new int[n]; what is this function actually doing? Open button in new window? How to open in default browser in C# Print in new line, java Deleting an object in C++

Examples related to object-create

Understanding the difference between Object.create() and new SomeFunction() Using "Object.create" instead of "new"