- Variables in JavaScript are containers for storing data values.
- They are declared using the
var
,let
, orconst
keywords. - Variables declared with
var
have function scope or global scope, while those declared withlet
orconst
have block scope. - It's recommended to use
let
orconst
for variable declarations to avoid issues related to scope and hoisting.
// Variable declaration with var (function-scoped)
var firstName = "John";
console.log(firstName); // Output: John
// Variable declaration with let (block-scoped)
let lastName = "Doe";
console.log(lastName); // Output: Doe
// Variable declaration with const (block-scoped constant)
const age = 30;
console.log(age); // Output: 30