Include Function

Quick reference

• 00:05 Okay, in this video I wanna talk about the include function.
• 00:07 Now, it's possible to include other files in your PHP file.
• 00:12 So there's a lot of reasons why you might wanna do this.
• 00:15 These days, if you go to any website,
• 00:16 they generally have a header at the to with a nav bar,
• 00:20 they have a footer at the bottom with links and copyright information.
• 00:24 They have menus sometimes on the left or the right side, and a lot of times,
• 00:28 you wanna create these dynamically, and
• 00:29 you wanna pull them from other files just a content management type of thing.
• 00:34 And we'll do this a little bit later on when we start templating out a website,
• 00:37 but one of the ways to do that is to use the include function.
• 00:40 So I'm gonna come over here and right click on our directory thing here and
• 00:44 click new file, and we're just gonna call this footer.php.
• 00:49 So let's open this footer.php file and let's just create echo and then say,
• 00:55 Copyright C and then the date.
• 01:00 Let's put space in there.
• 01:02 And we use our date function and let's say we want the year.
• 01:06 So if we save this and come back here to our index PHP file,
• 01:10 now let's say we wanna include this footer on our index page.
• 01:14 We would just use the include function which is include,
• 01:17 and most functions we use the parentheses.
• 01:20 We actually don't for this.
• 01:21 We just do this and go footer.php.
• 01:25 Now if we save this, come back here and hit reload, copyright c 2017.
• 01:30 That's really, really cool and really easy to do.
• 01:34 Now say, if you had like a website with 20 pages on it and
• 01:37 you wanted to include this footer on each of those pages,
• 01:41 you could just add this line of php code to the the bottom of each page.
• 01:45 And then later on, if you wanted to change this,
• 01:49 if you wanted to change this to copyright c,
• 01:53 John Elder and then All Rights Reserved.
• 01:57 Save this and when you come back to your main page and hit reload,
• 02:00 it automatically updates.
• 02:02 Now, if you had 20 pages or 50 pages or a thousand pages of your website,
• 02:06 this would update on every single one of those pages automatically and immediately.
• 02:11 And so that's really, really important for templating out websites.
• 02:14 So this is the include function.
• 02:16 One thing to note if say we change the name of this to footer 2, right, but here
• 02:21 on our index file, we're still calling footer.php, but there is no footer.php.
• 02:26 So what happens?
• 02:27 Well, if I click reload, boom.
• 02:28 We get this warning.
• 02:29 Now, this is just a warning.
• 02:31 The thing still executed.
• 02:32 In fact, we can see that by, let me type in all the things.
• 02:39 Now, let's do another line break.
• 02:42 We save this and hit reload.
• 02:44 It executes this but then we get a warning.
• 02:47 And in fact, we can copy this below, save it again, hit reload.
• 02:53 And her we have all the things.
• 02:54 So even though it couldn't find the file, the script still ran.
• 02:58 We just got a warning.
• 02:59 And that's important cuz a lot of times in PHP or other programming languages,
• 03:03 if you get an error, the whole thing crushes and stops.
• 03:06 But with include, you just get a warning and that's useful to know and
• 03:09 you'll see why in a little bit.
• 03:11 That's the include function, very useful.
• 03:13 In the next video, we'll talk about the require function.

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