2. [Functions:](./docs/functions.md)

- [Defining functions](./docs/functions.md#-defining-functions)

- [Calling functions](./docs/functions.md#-calling-functions)

- [Function arguments and return values](./docs/functions.md#-function-arguments-and-return-values)

- [Function Scope and closures](./docs/functions.md#-function-scope-and-closures)

- [Arrow functions](./docs/functions.md#-arrow-functions)

Functions are reusable blocks of code that perform specific tasks. It helps to organize the code, make it more modular, and for code reusability.

1. [Defining functions](#-defining-functions)

2. [Calling functions](#-calling-functions)

3. [Function arguments and return values](#-function-arguments-and-return-values)

4. [Function Scope and closures](#-function-scope-and-closures)

5. [Arrow functions](#-arrow-functions)

The functions are usable before defining it.

*Syntax:*

function functionName(parameter1, parameter2, ...) {

// Function body (statements to be executed)

return value; // Optional: Returns a value

}

function greet(name) {

console.log("Hello, " + name + "!");

}

To use function in the JavaScript code, that need to be called where it is required.

*Syntax:*

functionName(argument1, argument2, ...);

greet("Kumar"); // Output: Hello, Kumar!

**Arguments:** Values passed to a function that accepts as parameter of it when it's called.

**Return Values:** Values that a function can return to the where it was called or invoked using the return statement in the function.

function add(a, b) {

return a + b;

}

let sum = add(1, 2);

console.log(sum); // Output: 3

**Scope:** The region of code where a variable or function is accessible.

**Closures:** Functions that have access to variables from the outer scope, even after the outer scope has finished executing.

function outerFunction() {

let x = 10;

function innerFunction() {

console.log(x); // Accesses the outer variable x

}

return innerFunction;

}

let closure = outerFunction();

closure(); // Output: 10

It is defined in a concise way or in shorthand form.

*Syntax:*

(parameters) => expression;

let greet = (name) => {

console.log("Hello, " + name + "!");

};

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