JavaScript Functions
JavaScript Functions
A function in JavaScript is a block of code designed to perform a specific task. Instead of writing the same code again and again, you can put it inside a function and reuse it whenever needed.
Functions help make code modular, reusable, and cleaner.
✔ Function Syntax
To run (call) a function:
✔ Example
Output:
✔ Functions with Parameters
Parameters allow you to pass values into a function.
Output:
✔ Functions with Return Value
A function can return a value using return.
Output:
✔ Function Expressions
Functions can also be stored in a variable.
✔ Arrow Functions (ES6)
Arrow functions provide a shorter syntax.
✔ Self-Invoking Function
A function that runs automatically without being called:
Summary Table
| Type of Function | Example |
|---|---|
| Normal Function | function myFun() {} |
| Function with Parameters | function add(a,b){} |
| Return Function | return value; |
| Function Expression | const x = function(){} |
| Arrow Function | const x = () => {} |
| Self Invoking | (function(){})(); |
✔ Why Use Functions?
-
Reuse code (write once, use many times)
-
Makes code clean and organized
-
Helps in modular programming
