Variable Scope - Global, Local and Block Scope in JS

Variable Scope in JavaScript determines where a variable can be accessed or modified in the code. Global Scope variables are declared outside functions and can be accessed throughout the program. In contrast, Local Scope variables are declared within a function and are only accessible inside that function. For example, a let variable declared in a function is limited to that scope, while var behaves similarly but with functional scope.

Block Scope, introduced with ES6, is associated with variables declared using let and const. These variables exist only within the {} block they are defined in, making them inaccessible outside the block. However, var variables do not have block scope and are accessible outside blocks. These scoping rules ensure variable accessibility and security in JavaScript.

For more detail, please go through - What is Variable Scope in JavaScript ?