JavaScript Data Types - Numbers, Strings, and Booleans

JavaScript supports various data types that allow you to work with different kinds of values. In this guide, we'll explore three fundamental data types: Numbers, Strings, and Booleans.


Numbers in JavaScript can be integers or floating-point values. You can perform various mathematical operations with them. Here's how to work with numbers:

// Declare numbers
let age = 25;
let price = 19.99;
// Perform arithmetic operations
let sum = age + 5;
let product = price * 2;
// Use built-in Math object
let squareRoot = Math.sqrt(25);
console.log("Age: " + age);
console.log("Price: " + price);
console.log("Sum: " + sum);
console.log("Product: " + product);
console.log("Square Root: " + squareRoot);


Strings are sequences of characters and are commonly used for text. You can manipulate and work with strings in various ways:

// Declare strings
let firstName = "John";
let lastName = 'Doe';
// Concatenate strings
let fullName = firstName + " " + lastName;
// Find the length of a string
let nameLength = fullName.length;
// Access individual characters
let firstChar = fullName[0];
console.log("First Name: " + firstName);
console.log("Last Name: " + lastName);
console.log("Full Name: " + fullName);
console.log("Name Length: " + nameLength);
console.log("First Character: " + firstChar);


Booleans represent true or false values and are often used in conditional statements. Here's how to work with booleans:

// Declare booleans
let isStudent = true;
let isWorking = false;
// Use in conditional statements
if (isStudent) {
console.log("You are a student.");
} else {
console.log("You are not a student.");
if (isWorking) {
console.log("You are working.");
} else {
console.log("You are not working.");


Understanding JavaScript data types is fundamental for any programming task. Numbers, strings, and booleans are just a few of the data types you'll encounter when working with JavaScript. They serve as the building blocks for more complex data manipulation and logic in your code.

Happy coding!