Data Types in JavaScript

Data types in JavaScript are attributes that determine the type of value a variable can contain. These data types are used to represent different kinds of information.

JavaScript is a dynamically typed programming language, which means you don’t need to explicitly declare a variable’s type when creating it.

But that doesn’t mean JavaScript doesn’t have types. The type is simply determined automatically when a value is assigned.

Primitive Data Types

Primitive data types are those that represent single values and have no methods or properties. They are immutable, meaning they cannot be changed once created.

let age = 25;
let price = 99.95;

let name = 'Luis';
let message = "Hello, world!";

let isAdult = true;
let isActive = false;

let data = null;

let data;
console.log(data); // Output: undefined

Composite Data Types

Composite data types in JavaScript are those that can contain multiple values and have methods and properties. They are mutable, meaning they can change after creation.

let person = {
    name: 'Ana',
    age: 30,
    married: false
};

let colors = ['red', 'green', 'blue'];

Special Data Types

function add(a, b) {
    return a + b;
}

const id = Symbol('id');