WEBVTT 00:00.290 --> 00:03.980 Okay, so now let's learn about the functions in PHP. 00:04.370 --> 00:09.290 That's a really crucial topic to understand functions. 00:09.290 --> 00:14.090 So we're going to be talking about creating our own functions in PHP. 00:14.210 --> 00:23.900 But also PHP offers us the built in functions that are used to work, for example with arrays, strings, 00:23.900 --> 00:27.440 and actually quite a lot of other things. 00:27.590 --> 00:34.400 It's essential to just understand how functions work, what's possible, and what are the types of the 00:34.400 --> 00:35.210 functions. 00:35.210 --> 00:37.940 So you can also download this. 00:38.180 --> 00:40.850 Let's call it a board under this video. 00:40.850 --> 00:43.670 It might look a little bit complex though. 00:43.670 --> 00:47.390 It's actually everything that you need to know about functions. 00:47.390 --> 00:55.100 So we'll be zooming in to some specific parts of it while we work through the topic of functions. 00:55.100 --> 00:59.990 So let's immediately jump to the code editor and write our first function. 01:00.950 --> 01:08.120 So let's begin by creating a new folder for functions that will be functions. 01:09.650 --> 01:12.440 And let's create a new file. 01:12.470 --> 01:17.990 Maybe I can just call it a function because we're going to cover the basics first. 01:18.020 --> 01:20.210 The absolute basics. 01:20.690 --> 01:23.690 Let me add the starting tag. 01:25.190 --> 01:25.460 Okay. 01:25.460 --> 01:28.880 So let's start with how do you define your function. 01:28.970 --> 01:31.490 First you need the function keyword. 01:31.490 --> 01:35.630 And after that you need to come up with a function name. 01:35.630 --> 01:38.450 Then you always add the parenthesis. 01:38.450 --> 01:43.250 And inside those parentheses you can have some optional arguments. 01:43.250 --> 01:49.100 Some functions are fine without arguments, other others require some. 01:49.100 --> 01:57.590 Now with arguments you can use the optional type hinting for every argument like it can be an integer 01:57.620 --> 02:01.460 array may be an object of specific class. 02:01.460 --> 02:03.980 Then some arguments. 02:03.980 --> 02:07.550 They can be optional with optional arguments. 02:07.550 --> 02:14.990 You will provide the default value for them, and also you can have variadic arguments, which means 02:14.990 --> 02:19.160 that the number of arguments is not constant. 02:19.160 --> 02:29.550 You can, for example, pass Past two, 3 or 4 arguments, and then you can optionally define the function 02:29.550 --> 02:33.870 return type after the colon character. 02:34.110 --> 02:39.060 So we're not gonna cover all of this at once inside this video. 02:39.060 --> 02:41.760 Let's just start with a basic function. 02:43.800 --> 02:48.360 So a basic example would be to create a function called greet. 02:48.900 --> 02:53.910 So we can welcome someone and it will accept an argument called name. 02:53.910 --> 02:56.130 Let's keep the types for now. 02:56.130 --> 02:59.040 So then we need to add curly braces. 02:59.040 --> 03:00.540 They are required. 03:00.660 --> 03:04.200 And we would like to return something from this function. 03:04.200 --> 03:08.670 That's one of the best use cases for functions. 03:08.940 --> 03:15.750 You've got a basically a container which has some statements and has a given name. 03:15.750 --> 03:19.410 You pass something to it and it returns something back. 03:19.410 --> 03:27.150 So in this case, I'd like to return a string that would just greet the specific person using the past 03:27.180 --> 03:27.840 name. 03:27.870 --> 03:30.840 A super simple example, but it does the job. 03:30.870 --> 03:35.610 Now I'm going to echo the value returned from this function. 03:35.610 --> 03:38.190 And now how do we call a function. 03:38.190 --> 03:39.840 So that's also simple. 03:39.840 --> 03:44.880 You use the function name and your editor should already suggest this function. 03:45.480 --> 03:47.670 And then you need parentheses. 03:47.670 --> 03:49.860 They are always required. 03:49.890 --> 03:53.940 Now in this case this function requires one argument. 03:53.940 --> 03:55.650 So let's pass something. 03:55.830 --> 03:57.390 This can be a lease. 03:57.390 --> 04:02.910 Now let me go into this new functions folder and then run the function php. 04:03.210 --> 04:04.620 There we have it. 04:05.910 --> 04:08.400 The text was displayed inside the console. 04:08.400 --> 04:16.290 So that was the most basic example of defining a function with arguments and returning a value. 04:17.010 --> 04:24.210 Also, I think it's worth seeing what will happen if you will call a function that has a required argument 04:24.210 --> 04:25.410 without it. 04:25.440 --> 04:30.780 Let's try to call greet without any arguments. 04:31.140 --> 04:34.230 So we run php function PHP. 04:34.530 --> 04:41.430 So what happens is our PHP fatal error, which essentially stops the script at this point. 04:41.430 --> 04:45.930 So one thing to remember required arguments are required.