Require Function

Quick reference

• 00:04 In the last video, we talked about the include function.
• 00:07 In this video, I wanna talk about the require function.
• 00:10 And the require function is very similar to the include function.
• 00:13 In fact, they're basically identical.
• 00:15 You just require, save this, hit reload.
• 00:19 We get the same thing.
• 00:20 The main difference is with include, if there's a problem,
• 00:25 you get a warning and the script keeps going.
• 00:27 With require, it's required, and if it's not there, you don't get a warning,
• 00:32 the whole thing just shuts down.
• 00:33 So we can see, we named our file here footer.php,
• 00:36 and it just has this copyright statement in it.
• 00:39 And if we come up here and change the name of our footer file back to footer2,
• 00:43 you can see we've got all the things, the footer, and then all of the things.
• 00:48 So if we save this, come back here and hit reload,
• 00:50 that footer file is no longer there.
• 00:51 So we get all of the things, it tries to call footer2, it can't find it.
• 00:56 And instead of getting the bottom All the things..., we get nothing.
• 01:00 The program just stops.
• 01:02 So require, sometimes you want that.
• 01:04 So if you have a website that you really need something to come up on the website
• 01:08 and you want the whole thing to stop if it doesn't, use require and that will happen.
• 01:12 WordPress uses require, I believe.
• 01:14 Anyway, that's the main difference.
• 01:16 So what else can we do with this?
• 01:18 Let's come to our footer and let's rename this footer file back to footer.
• 01:22 Now let's create a variable called name and set it equal to John Elder.
• 01:31 We've required this file, and basically php is gonna pull this file in and
• 01:37 allow us to use it on our index page, right?
• 01:40 This is echoing something out, but it is also just setting a variable.
• 01:44 So we can access that variable wherever we want, here.
• 01:49 And do some more line breaks and let's create another php tag.
• 01:54 And let's just echo out that variable, we called it name, didn't we?
• 01:59 Yeah, name.
• 02:00 So if we save this file, come back here and hit reload, we have John Elder,
• 02:05 very interesting.
• 02:06 So here's something fun to try.
• 02:08 Take the php, take this line, and
• 02:10 let's put it up here above this require statement.
• 02:15 So if we save this, come back here and hit reload.
• 02:18 The thing disappears because with the flow of our program,
• 02:21 programming things start at the top and they come down the file.
• 02:25 So we're coming down to here, echoing out name.
• 02:27 Our program doesn't know what name is because we haven't added this file yet.
• 02:32 So this needs to come below this.
• 02:35 A common way to fix that might be to put this line at the very,
• 02:38 very top of your thing.
• 02:40 But if that happens, it's gonna echo out that at the top of the screen.
• 02:43 So that's just something to sort of keep in mind but that is require.
• 02:47 The main difference between require and include,
• 02:49 like I said, require will shut your program down if there's a problem,
• 02:53 include will just give you a little bit of a warning.
• 02:55 In the next video, we're gonna talk about forms and form handling.

Lesson notes are only available for subscribers.