Hello and welcome to another tutorial!

JavaScript tutorial!

I know all you guys need to make games, amazing websites... and more.
recommended for @Bookie0
So let's start!

1. Hello World!

A hello world example can be writed with 3 examples:

• In the console
• In the document
• In the alert

1. Console
   It is very simple... you only should write:

console.log("Hello World!");
// or
Console.log("Hello World!");

And then you just click inspect in the document and hit console and you should see:

Hello World!

2. Document
   In the first one, we printed hello world in the console...
   Now, we will print it in the document!
   Like this:

document.write("Hello World!");
// or
Document.write("Hello World!");

And then you should see in your document "Hello World!" in the left top of your document.

3. Alert
   VERY VERY VERY VERY Simple alert in javascript for hello world!

alert("Hello World!");

And then you should see an alert comes says "Hello World!"

2. Variables

Variables are so simple in javascript(let's call it js)...
you must write:

var a_string = "Hello World!";

and then you can write:

var a_string = "Hello World!";
// and then
console.log(a_string);
// or
document.write(a_string);
// or
alert(a_string);

Very simple!

3. If statements

If statements in js are so helpful!

you can write:

var name = "Zuhdi";

if(name === "Zuhdi"){
  alert("Hello Zuhdi!");
} else {
  alert("I don't know you.");
}

and then it will come an alert says "Hello Zuhdi" because name is equal to Zuhdi!

4. Comments

I don't need to late on comments...
you only should write:

// this is a comment

5. Functions

Functions are soooooo cooool in js!

you can write:

function add(num1, num2){
  var result = num1 + num2;
  return result;
}

then you shoudl CALL the function:

add(5, 17);

and the output will be 22

Why?

because in the add function we put in these () a num1 and num2... and when we call it, we wrote in the () our numbers

So...

THAT'S IT!

6. Simple Calculator with prompts and alerts.

From what we learned today: we need to make a simple calc!

let's start:

var num1 = prompt("First number:")
var num2 = prompt("Second number:")
var op = prompt("Operator:")
num1;
num2;
op;

if(op === "+"){
  alert(num1 + num2);
} else if(op === "-"){
  alert(num1 - num2);
} else if(op === "/"){
  alert(num1 / num2)
} else if(op === "*"){
  alert(num1 * num2);
} else {
  alert("INVALID!")
}

try this code and see the output!

ENJOY!