JavaScript : Data Types

In JavaScript, data types specify the type of data that a variable can hold. JavaScript is a loosely typed language, which means variables can hold values of any data type without explicitly specifying the data type. Here are the primary data types in JavaScript:

1. Primitive Data Types:

Primitive data types are the most basic data types in JavaScript. They include:

a. Number:
Represents numeric values, including integers and floating-point numbers.

let age = 30; let pi = 3.14;

b. String:
Represents textual data enclosed within single (' ') or double (" ") quotes.

let name = "John"; let message = 'Hello';

c. Boolean:
Represents a logical value indicating true or false.

let isStudent = true; let hasLicense = false;

d. Undefined:
Represents a variable that has been declared but not assigned a value.

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

e. Null:
Represents the intentional absence of any object value.

let car = null;

f. Symbol:
Introduced in ECMAScript 6 (ES6), represents a unique and immutable data type.

let id = Symbol("id");

2. Complex Data Types:

Complex data types are collections of data and are composed of primitive data types or other complex data types. They include:

a. Object:
Represents a collection of key-value pairs, where each value is accessed by a unique key (property name).

let person = { name: "John", age: 30, isStudent: true };

b. Array:
Represents an ordered list of values, accessed by index starting from zero.

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

Determining Data Types:

JavaScript provides the typeof operator to determine the data type of a variable or expression.

let x = 10; console.log(typeof x); // Output: "number"

let y = "Hello"; console.log(typeof y); // Output: "string"

Dynamic Typing:

JavaScript is dynamically typed, meaning the data type of a variable can change during the execution of a program.

let z = 10; z = "Hello"; // Now z holds a string value

Conclusion: