Variables and Data Types

Learn about JavaScript variables, const, let, and var declarations

Overview

Variables are containers for storing data values. JavaScript has three ways to declare variables:

const: Block-scoped, read-only variable. Use by default. let: Block-scoped, mutable variable. Use for values that change. var: Function-scoped, mutable (avoid in modern JavaScript).

JavaScript has several data types: String, Number, Boolean, Object, Array, null, undefined, Symbol.

Understanding data types is fundamental to programming in JavaScript. Each type has different characteristics and uses.

Variables and Data Types

Overview

Code Example