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And Lou, let's learn some JavaScript, we're going to open up Google Chrome here and we're going to

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go to view developer and this time JavaScript console so you can do command option J as well.

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And it opens up this console, which is, if you remember elements, you've seen it before.

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That's your e-mail console is where we can write JavaScript.

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On the right, you'll see the outline of what we'll talk about in this JavaScript segment, we'll go

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one by one and some of them will come back to.

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But don't worry, by the end, you'll know everything in here.

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So let's talk JavaScript.

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JavaScript has seven types.

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You can think of types as values that JavaScript can have.

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Let's start with the first one.

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And that is No.

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So the number type.

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Well, in JavaScript, you can do something like this.

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Look at that, the console allows us to write JavaScript as much as we want.

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So by writing this and the console, giving us an answer means that, yep, this is valid JavaScript.

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OK, what else can we do?

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Well, we can do.

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Three times five, fifteen, 12, divided by four, three.

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That's awesome, what else can we do?

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12 minus four.

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Eight.

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Now, can we do this?

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Can we do three plus four close the bracket times two, so that's seven times to 14?

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Yeah, it works and we can even do this.

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And this is a special character that you might have not seen before.

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It's called module.

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And let's see what happens.

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Gives me zero.

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Hmmm, what if I do 12 modulo five, it gives me to what this symbol does and let's make this bigger

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so you can see clearly.

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And I'm going to clear this just so you can see it better, and I can do clear here with these brackets

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and I'll clean up everything for me.

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So one more time, what I did was 12 modulo five, and that gives me two.

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And what module does is it gives me their remainder.

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So 12 divided by five is what gives me a reminder of two, because five can only go to ten and then

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you have to remind her.

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So if I do, let's say 12.

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Modulo five or let's do nine, I get a remainder of three and you're thinking, oh God, you're just

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you're just teaching me math.

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But don't worry, this is only a small part of it.

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I just want to show you that the first JavaScript type is a number and we can do operations on them

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just like a calculator can.

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The second type in JavaScript is.

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A strength.

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So a string is just text and all you need to do to let JavaScript know that you're writing a piece of

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text is double quotes.

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So I can just say, Bob.

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I can say my name and you can also use single quotes.

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And that is a strength, but what else can we do with the strength?

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Let me clear this.

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Well, you can also do this, you can say hello.

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Plus, their what do you think will happen here?

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Let's see.

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Hello there, but it is one word.

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We need a space, so we would have to do hello space plus.

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They're.

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And there we have the space.

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OK, so we can add things, so add two sentences together.

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What if we do?

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What if we do something like this?

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This isn't very nice.

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I hit enter and OK, that works, that's good, but what if I use single quotes here?

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What if I go like this?

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And remember I said that I can use single quotes and JavaScript?

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Well, you see the syntax changes.

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And I get a little error, well, because I'm using a single quote and then inside the string, I'm

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trying to use a single quote.

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And that would happen as well if I use double quotes.

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If we go back to the example before.

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And I add another quote in here.

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Well, again, I get an error, so let me clear that.

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How can we avoid this problem?

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Well, with the string in JavaScript, we can do something like this.

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This is the new single quotes.

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This isn't and what's this?

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This isn't very nice.

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And this backslash has a special meaning, the backslash says, hey, whatever comes after this.

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It's a special meeting means just ignore it.

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Don't say that this is a piece of string.

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I just want the Batek.

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So if I run like this now, oops, I made the Syntex over here wrong.

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Obviously the quotes need to match.

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So let's try that again.

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There you go.

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This is a very nice.

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OK, I have another question, what happens here?

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Ten plus.

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String of thirty four, so that's number ten plus string of thirty four, let's see what happens.

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Hmm, weird.

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So JavaScript automatically looked at this and said he's adding a number and a string, he's probably

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trying to add strings together.

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So JavaScript converts the number 10 into a string then and does ten thirty four.

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That's kind of weird, right?

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It's one of the quirks of JavaScript.

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There's a few of them.

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You just have to get used to it.

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Let's try something else.

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What about if I do ten minus three?

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Press enter.

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I get seven what is going on here, and because with the string, you can really subtract the string.

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I mean, let's see if I go.

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Hello?

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Minus.

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By.

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I get this weird symbol which will get back to you, but that doesn't work, so now JavaScript says,

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I'm going to.

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Because he's subtracting I'm just going to assume that he means the number three, so he's trying to

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help you out.

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But.

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Sometimes it can have unexpected behavior, so ideally you never do things like this ideal, you keep

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numbers with numbers and strings with strings, and you keep the actions between the like types.

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So let's go back to this, what just happened when I say hello minus by.

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Well, and and stands for not a number, and it's technically in JavaScript, you can see the blue highlighting

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here, it's part of the number type.

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So numbers can, you know, can range from one to 10 to, you know, five hundred sixty seven.

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But there's also the A.N. when it's saying, hey, whatever you just wrote is not a number.

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So that's the case as well.

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I know it's really, really confusing, but don't worry is just the quirks of the language that we're

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learning.

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OK, I'm going to show you one other JavaScript type before we get to some fun things in the next video.

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So the next one is Bolian.

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And the bullying type is very simple, bullying just means true.

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Or false, that's it, and sometimes that could be presented as ones and zeros, and for those that

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know a lot about computers, you might know that computer is pretty much runs on ones and zeros.

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And that's that's where it comes from.

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But booleans are very, very useful because now we can do something like three is greater than two,

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and I'll say true, three is greater than two if I do, five is greater than 10 will say false.

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Five is not greater than 10.

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We can also do five is.

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Greater than or equal to five, so we'll say true, because I can do greater than equal to and I can

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also do five is.

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Smaller than or equal to five.

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Now, what if I want to say, does three equal three?

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Hmm, I get an error.

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Why is that?

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Well, because in JavaScript, if you want to say something is equal to something, you have to say

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three equals three equals sign three.

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And I got through and in the next video, I'll tell you why that's the case, it's very, very interesting.

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But for now, just remember, that's always a tricky point that a lot of beginners get confused about.

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Disremember if you're comparing two things, three, equal.

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The last one I want to show you is this three doesn't equal three.

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Isn't that confusing?

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So this is saying.

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Thus, three not equal, three false, because three equals three.

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I know it can get really, really confusing, but think of this as the opposite of the equal sign.

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So, for example, if I do four doesn't equal five, I'll get you, because you're right, four doesn't

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equal five.

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So what we just learned are JavaScript comparisons.

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And there the things right over here.

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That's it.

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You just have to remember this.

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Oh, well, that was that was fun, right?

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But we're just getting started after this video.

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I have left an exercise for you.

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Try to find the answers to the problems and then copy and paste them each of the questions, each of

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the line into the JavaScript console.

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So, for example, if I said, you know, evaluate three plus five, you'll copy this.

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Put it in the console and just press enter and I want you to be comfortable working with console and

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playing around with it, experimenting around and like I said, really try and work on the next problem

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sets.

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I haven't given you a lot because I don't want you to get overwhelmed.

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There's a lot more interesting things happening in JavaScript than this, and you can pick this up fairly

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easily.

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But I do encourage you to make sure you do the exercises.

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Now, can you get all of them?

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Good luck.

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I'll see you in the next video.

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Bye bye.