Data Type in JavaScript

Data types are an essential concept in programming languages like JavaScript. They define the type of data that can be stored and manipulated in a program. Understanding data types is crucial for writing efficient and bug-free code. Let's explore the different data types in JavaScript:

1. Primitive Data Types:

These are the basic building blocks of data.

String:

• A sequence of characters.
• Defined with single (' ') or double (" ") quotes.

let greeting = "Hello, World!";

• Template Literals / Template strings

  • A special type of strings created using backticks(`)

  let info = `Know more about Template Literals`;
  • Allows multi-line strings

  let example = `This is an application 
              of template literals 
              in JavaScript `;
  • Allows string interpolation :- Template literals allow embedding variables and expressions directly into strings using '$'

  let num = 7,
    name = "Kim";
  let interpolatedString = `${name}'s lucky number is ${2 * num}`;
  //Kim's lucky number is 14

Number:

• Represents both integers and floating-point numbers.
• No distinction between integers and floats.

let age = 25;
let price = 19.99;

Boolean:

• Represents either true or false.

let isStudent = true;

Undefined:

• Variable declared but not assigned.

let undefinedVar;

Null:

• Represents the intentional absence of any object value.

let nullVar = null;

Symbol (ES6 and later):

• Provides a unique value, often used as identifiers.

let id = Symbol("id");

2. Composite Data Types:

These are used to store collections of data.

Array:

• Ordered list of values, accessed by index.

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

Object:

• Unordered collection of key-value pairs.

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

3. Special Data Types:

Function:

• A reusable block of code.

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

4. Type Coercion:

• JavaScript automatically converts one data type to another when needed.

let numString = "10";
let num = 5;

console.log(numString + num); // "105" (string concatenation)

5. Checking Data Types:

• Use typeof operator to check the data type of a variable.

let name = "John";
console.log(typeof name); // "string"

Understanding these data types is crucial for effective programming in JavaScript. They help you organize and manipulate data in your applications.