Understanding Functions in JavaScript

Source: Dev.to

What is a Function?

A function is a block of code designed to perform a specific task. Instead of writing the same code repeatedly, you can write it once inside a function and reuse it whenever needed.

Why Use Functions?

• Reduce code repetition
• Make code easier to understand
• Help in organizing large programs
• Allow reuse of logic

How to Create a Function

In JavaScript, you can create a function using the function keyword.

function greet() {
    console.log("Hello, welcome to JavaScript!");
}

How to Call a Function

To execute (run) a function, simply call it by its name:

greet();

Output

Hello, welcome to JavaScript!

Functions with Parameters

Functions can take inputs called parameters.

function greetUser(name) {
    console.log("Hello " + name);
}

greetUser("Athithya");

Output

Hello Athithya

Functions with Return Value

A function can return a value using the return keyword.

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

let result = add(5, 3);
console.log(result);

Output

8

Reference

MDN Web Docs – Functions