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Cover image for This Keyword Scenarios in JS
Umashankar S
Umashankar S

Posted on • Updated on

This Keyword Scenarios in JS

This Keyword:-
It is an Object, that is executing the current function.
But, this keyword behaviour is different in different situations.


1. Global Space :- this keyword will always point to the global window object in global space.

console.log(this); //global window object
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2. Normal Function:- If we wrote the normal function in global space, that function will always point to the window object, so if we print "this" inside a function. that will always be widow object.

function User() {
    console.log(this) //global window object
}
User();
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3. Objects:- If we consider an object, functions inside the object will always have the parent. so "this" will not point to the global object. instead of that, it will point the particular object.

const data = {
  name: 'uma',
  age: 22,
  address: function() {
    console.log(this.age) //22
  }
}

data.address()
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Note:- But Arrow Function will always point to the window object.

const data = {
  name: 'uma',
  age: 22,
  address: () => {
    console.log(this.age) //undefined
  } 
}
data.address()
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4. Constructor:- Constructor also have the same behaviour as Objects. it will also point to the particular object.

function User(name) {
  this.name = name,
  console.log(this.name)  //uma
}

const user1 = new User('uma')
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Thanks for reading!

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richardknoche2 profile image
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Richard Knoche (He/Him)

False/ misleading: what this refers to doesn't depend on where it's used but rather on how it's called (aka its call-site). I recommend you check out the you don't know JavaScript book.

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