This in javascript

• This in javascript for normal function refers to object by which it is called
• This in javascript for arrow function refers to object where it is defined

Ex.1

var name = 'Neeraj Dhakar';
function displayNameByNormal() {
  console.log('display name using normal function: ', this.name);
}
const displayNameByArrow = () => {
  console.log('display name using arrow function: ', this.name);
}
const obj = {
   name: 'Arvind Dhakar',
   displayNameByNormal: displayNameByNormal,
   displayNameByArrow: displayNameByArrow
}
obj.displayNameByNormal();
obj.displayNameByArrow();
Output: 
display name using normal function:  Arvind Dhakar
// since displayNameByNormal is a normal function so this keyword here refers to object by which it is called (in this case obj)
display name using arrow function:  Neeraj Dhakar
// since displayNameByArrow is a arrow function so this keyword here 
// refers to object where it is defined (in this case global window // object)

Ex.2

var name = 'Neeraj Dhakar';
const obj = {
  name: 'Arvind Dhakar',
  sayHi: function () {
     console.log(' just say Hi to ', this.name);
     function insideNormal() {
       console.log('say Hi inside normal function to ', this.name)
     }
     const insideArrow = () => {
       console.log('say Hi inside arrow function to ', this.name)
     }
  
     insideNormal(); 
     insideArrow();
  }
}
obj.sayHi()
Output:  
just say Hi to  Arvind Dhakar 
// since sayHi is a normal function so this keyword here refers to object by which it is called(in this case obj)
say Hi inside normal function to  Neeraj Dhakar
// since insideNormal is a normal function so this keyword here 
// refers to object by which it is called (in this case global     // window object)
say Hi inside arrow function to  Arvind Dhakar
// since insideArrow  is a arrow function so this keyword here 
// refers to object where it is defined ( in this case obj)