Data Types in JavaScript: Primitive & Non-Primitive

What are Data Types?

JavaScript is dynamically typed, meaning variable types are determined automatically at runtime based on the assigned value.

Primitive Data Types

• String — textual data, e.g. "Hello"
• Number — integers and floating-point numbers, e.g. 25, 3.14
• Boolean — true or false
• Undefined — a variable declared but not assigned a value
• Null — represents an intentional absence of value
• BigInt — for very large integers
• Symbol — a unique and immutable value, often used as object keys

Non-Primitive (Reference) Data Types

• Object — collections of key-value pairs
• Array — ordered lists of values
• Function — reusable blocks of code, which are also objects in JavaScript