What Are Data Types in JavaScript?

What Are Data Types in JavaScript?

Data types define the kind of value a variable can hold.

Understanding data types is a fundamental JavaScript concept.

Primitive Data Types

JavaScript provides several primitive data types:

• String
• Number
• Boolean
• Undefined
• Null
• BigInt
• Symbol

These values are immutable.

String

Used for textual data.

Example:

let name = "John";

Number

Used for numeric values.

Example:

let age = 25;

Boolean

Represents true or false.

Example:

let isLoggedIn = true;

Undefined

A variable declared but not assigned a value.

Null

Represents an intentional absence of value.

Non-Primitive Data Types

The primary non-primitive type is:

• Object

Examples include:

• Objects
• Arrays
• Functions

Why Are Data Types Important?

Data types help developers:

• Store Data Efficiently
• Avoid Bugs
• Write Predictable Code
• Understand Memory Behavior

The Bottom Line

JavaScript data types determine how values are stored and manipulated. Understanding them is essential for writing reliable JavaScript applications.