Docs/JavaScript/Functions

JavaScript Functions

  • Declaration: function name() {}
  • Expression: const name = function() {}
  • Arrow: const name = () => {}

Fitur

  • Default parameters
  • Rest parameters (...args)
  • Return value
  • IIFE (Immediately Invoked Function)
script.js
Try It →
function greet(name) { return "Hello, " + name + "!"; }
const add = (a, b) => a + b;
const welcome = (name = "Guest") => "Welcome, " + name + "!";
function sum(...nums) { return nums.reduce((a,b) => a+b, 0); }

const o = document.getElementById('output');
o.innerHTML = 
  'greet("World") → '+greet("World")+'
'+
  'add(5, 3) → '+add(5,3)+'
'+
  'welcome() → '+welcome()+'
'+
  'welcome("Ali") → '+welcome("Ali")+'
'+
  'sum(1,2,3,4,5) → '+sum(1,2,3,4,5);