JavaScript Data Types

JavaScript variable can hold

Data Types and

Type

Description

Number

A number representing a numeric value

Bigint

A number representing a large integer

String

A text of characters enclosed in quotes

Boolean

A data type representing true or false

Undefined

A variable with no assigned value

Null

A value representing object absence

Symbol

A unique primitive identifier

Object

A collection of key-value pairs of data

Examples

// Number let length = 16;
let weight = 7.5;
// BigInt let x = 1234567890123456789012345n;
let y = BigInt(1234567890123456789012345)
// Strings let color = "Yellow";
let lastName = "Johnson";
// Boolean let x = true;
let y = false;
// Undefined let x;
let y;
// Null let x = null;
let y = null;
// Symbol const x = Symbol();
const y = Symbol();
// Object const person = {firstName:"John", lastName:"Doe"};
// Array Object const cars = ["Saab", "Volvo", "BMW"];
// Date Object const date = new Date("2022-03-25");

The Concept of Data Types

let x = 16 + "Volvo";
Does it make any sense to add "Volvo" to sixteen? Will it produce an error or will it produce a result?

let x = "16" + "Volvo";

Example

let x = 16 + "Volvo";