Data Types In JavaScript

 In JavaScript, data types define the type of values that can be stored and manipulated by a program. Here are the main data types in JavaScript, along with details and examples:

1. Primitive Data Types:

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

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   • let num = 10; let pi = 3.14;

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

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   • let message = 'Hello, world!'; let name = "John Doe";

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

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   • let isTrue = true; let isFalse = false;

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

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   • let undefinedVar;

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   • Null: Represents an intentional absence of any value.

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   • let nullVar = null;

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   • Symbol (ES6+): Represents unique identifiers and is often used as property keys in objects.

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   • const sym = Symbol('description');

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2. Composite Data Types:

   • Object: Represents a collection of key-value pairs, where keys are strings (or symbols) and values can be of any data type.

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

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   • Array: Represents an ordered list of values, accessible by numerical indices starting from 0.

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   • let numbers = [1, 2, 3, 4, 5];

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3. Special Data Types:

   • Function: Represents a reusable block of code that can be executed when called.

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   • function greet(name) { console.log('Hello, ' + name + '!'); }

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   • Date: Represents a specific date and time.

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   • let today = new Date();

These are the main data types in JavaScript, each serving different purposes and allowing developers to work with various kinds of data effectively.