Understanding Functions and Arrow Functions in JavaScript

Output will be Hello Alice
greet is a regular function, so when user.greet() is called, this inside greet refers to the user object.

• Inside greet, it returns an arrow function.

• Arrow functions do not have their own this. They lexically inherit this from their surrounding scope — in this case, the greet function.

• Since greet was called on user, this in greet points to user, and so the arrow function also "remembers" that this.

In this match output will be undefined and 25
Since sayAgeArrow: Is a arrow function so it don’t have own this and it inherit from lexical env so in this case it refer to window obj in case of browser and in case of node it refer to global object that is undefined So that is the reason it’s print undefined
sayAgeRegular: Is a regular function so it have it own this and here this will point to person object so it will return 25 (this.age)

Higher Order Function

Output => 8,2