What is Object Destructuring?

Object Destructuring is a new and cleaner way of getting or extracting values from an object or an array.

Suppose we have an object that looks like this.

const employee = {
  firstName: "Marko",
  lastName: "Polo",
  position: "Software Developer",
  yearHired: 2017

The old way of getting properties from an object is we make a variable that has the same name as the object property. This way is a hassle because we're making a new variable for every property. Imagine we have a big object with lots of properties and methods using this way in extracting properties will be irritating.

var firstName = employee.firstName;
var lastName = employee.lastName;
var position = employee.position;
var yearHired = employee.yearHired;

If we use object destructuring it looks cleaner and takes a little time than the old way. The syntax for object destructuring is that if we are getting properties in an object we use the {} and inside that, we specify the properties we want to extract and if we are getting data from an array we use the [].

let { firstName, lastName, position, yearHired } = employee;

If we want to change the variable name we want to extract we use the propertyName:newName syntax. In this example the value of fName variable will hold the value of the firstName property and lName variable will hold the value of the lastName property.

let { firstName: fName, lastName: lName, position, yearHired } = employee;

We can also have default values when destructuring. In this example, if the firstName property holds an undefined value in the object then when we destructure the firstName variable will hold a default of "Mark".

let { firstName = "Mark", lastName: lName, position, yearHired } = employee;