JS Functions

A function is defined once and can be called (invoked) as many times as needed. This prevents code repetition and keeps your programs organised.

Syntax:

function functionName(parameter1, parameter2) {
  // code to run
  return result;
}

Try It — Functions in Action

Key Concepts

Concept	Description	Example
Definition	Declare the function	function add(a, b) { ... }
Parameter	Input the function receives	a and b above
Return	Value the function sends back	return a + b;
Invocation	Calling the function	add(3, 5) → 8

Tip: Functions that return a value can be used directly in expressions: let result = multiply(4, 3) + 10;