Hello, in this video we are going to look at including and requiring files. So just having one file can, you know, become tedious. And it can also, you know, it's just not very easy to manage your code. So you might create another file, for example, let's say Oculus header. And this has to be a PHP. So we'll create a new one called footer.

Php. And what we could do is on all the pages, we want to get the data from the head and get the date from the footer. Maybe the header is complicated. php, we can put HTML as well. So you could put, you know, all the doctype and all that stuff, but I was gonna keep it simple. So PHP, code is the header and then I'm going to put a new line tag basically copy that for the footer.

And in here if I was to just to reload this, nothing's showing. And if I want to actually use it, we need PHP tags. And we just put include, and then we put the name of the file. Actually, more specifically, we put the location. In this case, it's in the same folder, but within a subfolder to put the location and then we put include footer, dot php, semi colon. Okay, so this is the header.

This is the footer. So we haven't wrote that he has got all the code from the variable that we get. We could have separate classes in there could be a bunch of stuff that could be functions. He could maybe have a user account. While there has no class in there are bunch of functions. And you can just use that in multiple files.

So it allows you to reuse the code that you've already written. So let me show you what happens. If I want to put something here and say echo your main body, put a new tag here, a new line tag, there we go. What happens if I put that so I made a mistake in spelling and that file doesn't exist. This happens, we get a warning, that's fine. You can disable warnings, you know, in a separate way, but the rest of the code still runs if this file is so crucial that you need it for the rest of the No, you know, website to run, you know the rest of the file, then what you can do in common.

So, you can use require and and then suggested with quite a bit, the same as include because as you can see works the same as include. But if I do a spelling mistake, no reload, we get an error, but the rest of the file does not execute. So he exits from there. There's another one that I want to show you. And this is called require or include once. And what that does, so if I wanted to duplicate this, I didn't see printed out twice, this could be a problem.

If the variables are classes of functions in the file, there'll be duplications and that will produce an error if I just put require on the school once and the same will be included. So the only difference between the two require is require needs the file if it doesn't, it will hold the rest of the execution won't work the same for both So if I run this now, I'm still requiring the header twice. But it only actually includes the ones clip detects, it's already been required. It's already been, you know, you know, added. And that is actually the case, if you know inside of the header file that includes all records in our file. And if we have a no file that we've required, and that includes requires that other file, you will only include it or require it once if we do that require or include once.

So that's it. That's how you separate out your code. Now the vacuum cleaner is being used there, maybe Can you remember you can't it's time to end the video. Anyway. So thanks for watching, and I look forward to seeing you in the next video.