javascript closure simple explanation

What is Closure?

A closure is that the combination of a function and therefore the lexical environment within which that function was declared.

A closure is an inner function that has access to the outer (enclosing) function’s variables — scope chain. The closure has three scope chains: it's access to its own scope (variables defined between its curly brackets), it's access to the outer function’s variables, and it's access to the worldwide variables.

Let see a closure example below:

  

function User(name){  var displayName = function(greeting){
   console.log(greeting+' '+name);
  }
return displayName;
}var myFunc = User('Raj');myFunc('Welcome '); //Output: Welcome Raj
myFunc('Hello '); //output: Hello Raj

In this code, We have an outer function User() which returns an inner function as displayName(),

The inner function will have access to the variables in the outer function scope, even after the outer function has returned.