How did it go?

If you didn't get it to work, you can watch my solution

compared to what you wrote and then try to recreate it yourself.

Also, keep in mind,

there are usually many different ways to solve a programming challenge.

Your solution may be different than mine and still work, that's fine.

So the first thing that I'll do is I'll move the declarations for the num2 and

message variables to the top of the math.js file.

I'll also remove the var keywords from down below.

This practice session requires that you use a conditional statement.

But where should you put it?

Let's look at the requirements again.

I'm supposed to check the values of the inputs, are they numbers or not?

So I can put the conditional statement right after I collect input from the user.

So I start with the if clause, followed by a condition in parentheses,

and braces to mark the opening and closing of the conditional.

Anything I add in here will run only if number 2 is equal to 0.

I'll add an alert Message.

Let's see how this works, I'll save and preview the file.

Type a number for the first input, and 0 for the second.

Excellent, here's the alert.

Uh-oh, unfortunately, it still prints to the page,

that's because the rest of the program is outside of the conditional statement.

We need to add an else clause to stop the programming from generating and

writing this message.

I'll add an else clause and another set of brackets.

Okay, I'll save the file and preview again.

Great, I get the alert message, but nothing is printed to the doc,

that's perfect.

But I also want to check that both inputs are numbers.

I can add a branch to this conditional statement.

I'll do that using an else if clause.

To check to see if a variable holds a number,

you can use the is not a number method.

So I'll first check to see if the num1 variable is a number.

Inside these brackets, I'll add the alert message that appears if the user types

in text in the prompt dialogue.

But we also need to check the second number.

One way you could do this is adding another else if clause to test

the second number.

But that would be extra programming that's just not necessary.

Another way to do it is add two pipe characters,

followed by a second condition.

The pipe characters indicate that either one or

the other of the test have to be true.

In other words, if either number one is not a number or

number two is not a number, we should alert the user.

At this point, we have conditional statements with three branches.

The first two test for errors and the last writes a message.

Let's check it out.

I'll leave the first input blank and then type hello in the second, excellent.

And when I reload it and use numbers, it works.

I hope you're able to complete this practice successfully.

If not, why not start over and

try to write the program without looking at my version.

Have fun with JavaScript, and see you again soon.