Basic.js

//# ON PAGE SCRIPT
<script type="text/javascript"></script>;

//# INCLUDE EXTERNAL JS FILE
<script src="index.js"></script>;

//# FUNCTION
function myFunction() {
  return a + b;
}

//# COMMENTS
/* Multi line */
// One line

//# BORDER WIDTH
console.log(a);
document.write(a);
alert(a);
confirm("Realy");
prompt("Your age?", "0");

//# Data Types
var age = 18; // number
var name = "therogersak"; // string
var person = { name: "therogersak", age: 18 }; // object
var sheets = ["HTML", "CSS", "JAVASCRIPT"]; // array
var a = undefined; // undefined
var b = null; // null

//# IF-ELSE STATEMENT
if (age > 18) {
  console.log("Nice");
} else {
  console.log("Not Eligible");
}