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JavaScript

JavaScript Functions

JavaScript functions bundle reusable blocks of code.

Read Time

5 min read

Difficulty

Beginner

Last Updated

Jun 15, 2026

Version

v1.0.0

Introduction

JavaScript functions store instructions that you want to use multiple times. Instead of copying and pasting the same ten lines of code, developers wrap them inside a function and call its name whenever needed.

Syntax

1/* function syntax */
2function myFunc(param) {
3  // Code runs here
4}

Example

1/* this creates a function */
2function multiply(a, b) {
3  return a * b;
4}
5
6let result = multiply(4, 3);

Key Points

The `function` keyword creates the block.
Parentheses hold incoming variables called parameters.
Curly braces contain the actual code to execute.
The `return` keyword sends data back.

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