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.this Explained in the most Simple Way!! (JavaScript) ✨

Rajdeep Sengupta

Published on : Aug 06, 2023

.this Alone refers to the global object.

Now What is global Object?

In JavaScript everything is considered as object, so the whole window displayed by the browser is also a JavaScript object .

Code Example:

javascript

console.log(this);

This statement in a .js/.jsx file only refers to the Window object.

In case it is just a normal function .this refers the same means Global Object.

javascript

//This is the example of a regular function.

function sum(){
	var add = 2+2;
	console.log("Sum of two number is: " +  add);
	console.log(this);
}

sum();

//Here ".this" doesnot refer to the sum() function this still refers to the global function.

In a method:

In a method ,this refers to the owner object.

What is a Method?

When you make a function in a java Script Object then it is called as method. Method of that parent object.

Example of a method:

javascript

const note={
    name: "Rajdeep Sengupta",
    class: "1st Year B.tech",

    sum: function(){
        var add= 2+2;
        console.log("Sum of this tow number is:  "+ add);
        console.log(this);
				console.log(this.name);
    }
}

note.sum()

Output:

javascript

//Result in the console pannel.

Sum of thois tow number is:  4

//here .this console logs the whole parent object.Which is 'note

Object
class: "1st Year B.tech"
name: "Rajdeep Sengupta"
sum: ƒ ()
[[Prototype]]: Object

//here it console logs the Name as expected. By (
.this.name)
Rajdeep Sengupta

Strict Mode:

Example of Strict Mode:

javascript

"use strict"

function sum(){
	var add = 2+2;
	console.log("Sum of two number is: " +  add);
	console.log(.this);
}

But here even though it is a regular Function it will not give a the Global Object. This will be simply Undefined.

For More info Visit this Link.

this - JavaScript | MDN