JavaScript Data Types

JavaScript has several data types that can be broadly categorized into two groups: 

• Primitive data types
• Object types

Primitive Data Types 

JavaScript has six primitive data types:

• String: Used for text data. Enclosed in single or double quotes.
• Number: Represents both integers and floating-point numbers.
• Boolean: Represents true or false values.
• Undefined: Represents the absence of a value or an uninitialized variable.
• Null: Represents the intentional absence of any object value.
• Symbol: Introduced in ECMAScript 6, symbols are unique and immutable primitive values.

let myString = "Hello, World!";
let myNumber = 42;
let isTrue = true;
let myUndefined;
let myNull = null;
let mySymbol = Symbol('unique');

Object Data Type

Object: An unordered collection of key-value pairs.

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

Special Data Types

Function: A reusable block of code that can be defined and called.

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

Array: An ordered collection of values, accessible by indices.

let myArray = [1, 2, 3, 4, 5];

Type Checking: JavaScript provides the typeof operator to check the data type of a variable.

console.log(typeof myString); // Outputs: string
console.log(typeof myNumber); // Outputs: number
console.log(typeof isTrue);   // Outputs: boolean

Type Conversion: You can convert between data types using functions like parseInt(), parseFloat(), and String().

let numString = "42";
let convertedNum = parseInt(numString);

 

Understanding JavaScript data types is crucial for effective programming and avoiding unexpected behaviors.