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So it's time for a five minute crash course of node and JavaScript.

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Obviously, that's not enough time to even scratch the surface, but I'm just going to show you the

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basics of what you need to know for us to continue on with the course.

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OC So back over in Cloud nine, we will delete everything.

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Get rid of it so you can do that either.

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If you want to use a command line, you could do use arm and dash RF or just.

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Highlight what you need to delete right click and where is that delete?

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And then we'll say yes to all.

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We want to remove all of it and we're home free now.

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Can get rid of some of this stuff.

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Perfect.

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Make some space.

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I'll bring this up a bit.

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And now all that we're going to do is make our first JavaScript file.

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We can call it whatever we want.

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You can either use touch apks or you don't have to call it JS or you can right click over here and click

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on New File.

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I'll do that one and I will call this well I'll do JS.

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It's a standard name.

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And I won't recreate it down here.

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Now we'll open it up, double click, and we'll add some JavaScript in here.

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So what I want to show you is this basic workflow with Node that we kind of saw already.

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We typed some code in the file, we save it, and then we execute the file with the command node space

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and then the name of the file.

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So it's very similar, at least in principle, to what we did with the SQL Files, where we would save

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a SQL file ending in SQL.

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Put something in there, a query, then we would execute it using source and then some file name dot

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SQL.

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Same idea.

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So I'm going to show you some very simple code.

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There's something called.

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And again, if you know this stuff, feel free to skip it.

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Something called console.log.

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Kind of the simplest possible command you can do in my SQL.

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It will just print something out so we can do our basic.

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Hello.

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Oops, we don't need caps.

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Hello world.

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And we'll put a semicolon there, which should seem familiar from my SQL at least.

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And let's start with this.

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Our first application, very basic.

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If all we need to do to execute it is come down here and type node and the name of the file which we

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called app dot js.

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And it runs silly, but it works.

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Okay, so that doesn't seem useful, of course, but it's something, right?

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And to see kind of why a programming language would be useful, let's at least do this 500 times.

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Let's.

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Maybe that's not useful, but we can at least see how it's helpful.

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It's doing something that we can't do on our own so we can create a simple loop.

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We'll do less than 500.

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Now, in my other courses, this is like an entire video, five or 10 minutes with exercises, but I'm

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not going to spend time on that.

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What this here does is it says whatever's inside of here repeat 500 times.

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Basically, this is a counter saying, okay, we're starting at zero.

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And every time through the loop we're going to add one to I, which is what this does here.

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So we go zero next time around.

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One, two, three, keep going.

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While it's less than 500.

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As soon as it hits 500, we're done.

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Okay, so if I just put that in there, whatever is in these brackets here will happen 500 times.

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Let's do it.

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Now, one thing that I could add that I probably should is this var keyword.

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It's just don't worry about it, but it's important to have it there.

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Now, if I run it and I scroll up, I can see we get hundreds of hello world's well 500 so imagine you

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might be wondering why do you care.

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Well, imagine instead of console.log what if we had insert a new user into the database?

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That would be a fantastic way to quickly see the database with a bunch of data.

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Remember how we had to do this obnoxious copy and paste?

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So I would give you a file.

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You would copy and paste.

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Like for the movies, data and review service, these big files you had to copy and paste it in.

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It's an awful way of of getting sample data.

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Well, we can use JavaScript to create data for us.

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So just a couple other things that I'll show you.

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We can do math and basic things like five plus five and I won't do this 500 times.

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We can comment things out, selecting them and doing command slash so that won't run anymore.

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So now I'm only running five plus five.

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You can see we get ten.

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One other thing to address is what?

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What is Node if you're not familiar with it and it's actually a pretty common question.

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There's a bit of confusion about Node Node.js, which is what it's called, and regular JavaScript and

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what the difference is.

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Basically, JavaScript is a programming language.

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It was created first.

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It's been around for a while and it's existed as a language that you can use on the client side.

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So what that means is that back on this diagram, there's a line right here, not right now, but imagine

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a line.

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This is the client side.

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So I could write JavaScript code that did things over on someone like on my computer.

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You could write code that would animate something or make a game or just add some pretty effects.

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That's not to say that it's not powerful, but traditionally it was used kind of to decorate pages,

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if you will, and it had nothing to do with databases.

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It had nothing to do with servers.

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You would use another language over here like PHP and you would use JavaScript on the client side of

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the front end.

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But then Node came around about five years ago now and what it is, is an implementation of JavaScript

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written so that you can use it on the back end, so that you can do things like this.

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You can create a server with JavaScript instead of having to do it with Ruby or PHP, and it can talk

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to a database like any other server side language.

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So to summarize that node is JavaScript.

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It uses basically the exact same syntax, but you can use it on the back end, which is what we'll be

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doing in this course.