Function scopes and block scopes in JavaScript

In this tutorial we are going to discuss what is Function scopes and block scopes in JavaScript. In javascript Block scopes are different from function scopes and lets see the below example, then you will get more understanding on this.

Function Scope :

A function scope is created for every function (and we can nest them too). Lets see the below simple function scope example.

Example -1 :

function add() {

  // function scope
  
}

Lets see the example for nested function.

Example -2 :

function add() {

  // local function scope

  function sum() {
    // nested local function scope
  }

}

Block Scope :

Block scopes are what you get when you use if statements, for statements etc. Lets see the below example for block scope.

Using if statement

if (4 == '4') {
  // block scope for the if statement
}

Using for statement

for (var i=0; i<10; i++) {
  // block scope for the for statement
}

This is all about Function scopes and block scopes in JavaScript. Thank you for reading this article, and if you have any problem, have a another better useful solution about this article, please write message in the comment section.