WEBVTT 00:00.500 --> 00:03.680 Okay, so let's do a deeper dive on arrays. 00:03.710 --> 00:11.510 Now we've been using arrays previously, but now in this video we are just gonna focus on them entirely. 00:11.510 --> 00:13.880 So we've got a simple array here. 00:14.030 --> 00:20.900 Um this is just indexed automatically by PHP starting with zero. 00:20.900 --> 00:30.410 And then another example is an associative array where we choose the keys and assign values to them. 00:31.520 --> 00:34.040 Now both arrays are or. 00:34.040 --> 00:37.160 The values from both arrays are read the same way. 00:38.120 --> 00:45.950 So you either use a number index like zero, or you use the key from the associative array. 00:45.980 --> 00:48.590 This key needs to be defined there. 00:48.620 --> 00:52.100 So in this case it's for example name. 00:52.100 --> 00:58.760 And when I run this we see one because that's the first element in this array. 00:58.760 --> 01:03.080 And we see John because this is under the name. 01:05.210 --> 01:08.420 Next up to add elements to an array. 01:08.540 --> 01:12.200 Let's start with the simple indexed array. 01:12.650 --> 01:19.220 You just use this syntax square brackets next to the variable name next to the array. 01:19.610 --> 01:21.680 And you can add anything. 01:21.680 --> 01:28.670 Let's say we add six elements are always added at the end of this indexed array. 01:28.910 --> 01:35.630 Now with associative array which is a little bit different you need to choose the key. 01:36.680 --> 01:42.230 So we can add a country which can be USA. 01:44.840 --> 01:49.370 So in PHP you can also have multi-dimensional arrays. 01:51.080 --> 01:58.940 So we can just add an array inside an array like this matrix that I've created in here. 02:01.430 --> 02:09.590 Though it's also possible that inside an indexed array like this one, you can add an associative array 02:10.730 --> 02:14.840 and you access the elements using square brackets. 02:16.430 --> 02:20.150 So this is getting the second array from matrix. 02:20.150 --> 02:27.380 And from this array I'm also getting the second element which should display five. 02:27.380 --> 02:29.780 So let me comment out those. 02:29.780 --> 02:32.270 So we clearly see the result. 02:32.270 --> 02:35.570 So I expect to see five on the screen. 02:35.570 --> 02:36.740 And there it is. 02:38.150 --> 02:38.450 Okay. 02:38.450 --> 02:42.320 So next up let's see some functions that we can use with arrays. 02:42.320 --> 02:44.750 So we've got this fruits array. 02:45.140 --> 02:50.330 We can count them using the count function. 02:52.880 --> 02:55.070 So it should display three. 02:55.730 --> 02:58.480 And then we can sort arrays. 02:58.510 --> 03:05.560 So with sorting, you need to know that sorting works in place, which means the original array would 03:05.560 --> 03:06.820 be modified. 03:09.640 --> 03:16.930 So let's vardump this and the sort function is doing an ascending sort. 03:16.990 --> 03:21.070 So to have a descending sort you do a sort. 03:21.850 --> 03:26.050 Again this also modifies this variable. 03:26.560 --> 03:28.870 It doesn't return a new one. 03:29.050 --> 03:29.350 Okay. 03:29.380 --> 03:31.570 So let's also vardump this. 03:31.600 --> 03:37.210 I'm going to comment out this line and let's run this script. 03:37.420 --> 03:39.910 So the count of elements is three. 03:39.940 --> 03:48.640 Then the elements when sorted in ascending order we've got this fruits and then sorted in descending 03:48.640 --> 03:49.300 order. 03:49.330 --> 03:50.710 That's the order. 03:51.820 --> 03:52.120 Okay. 03:52.120 --> 03:55.210 Now let's do something with associative arrays. 03:55.210 --> 03:59.080 First let me dump the associative array. 03:59.110 --> 04:00.730 Um, what's the name of it? 04:00.760 --> 04:03.670 Okay, that's just associative array. 04:04.840 --> 04:14.560 Now you can also sort the associative arrays, but here we can sort the elements by key or by value. 04:14.590 --> 04:15.430 Okay. 04:15.490 --> 04:19.780 Um a sort will sort by value. 04:23.230 --> 04:24.010 Okay. 04:24.010 --> 04:25.570 Let's vardump. 04:25.570 --> 04:28.420 This also sorts the array in place. 04:28.420 --> 04:31.390 So it is modifying the original variable. 04:32.170 --> 04:34.510 Then we've got k sort. 04:35.380 --> 04:39.070 This as you can guess is sorting by keys. 04:42.250 --> 04:46.240 Let's also vardump that one. 04:48.310 --> 04:49.180 Okay. 04:49.180 --> 04:50.620 Let's run it. 04:51.640 --> 04:59.590 So that's the original array in the order that we have defined that we've also added a country in at 04:59.590 --> 05:00.580 one place. 05:01.150 --> 05:04.630 Then we sorted using a sort. 05:04.630 --> 05:08.170 So this was sorting by value. 05:08.680 --> 05:09.850 That's the result. 05:09.880 --> 05:13.750 And this here is sorting by key. 05:14.410 --> 05:18.280 As you can see keys seem to be sorted alphabetically. 05:20.500 --> 05:20.770 Okay. 05:20.770 --> 05:23.620 So next up let's create some numbers. 05:24.880 --> 05:28.600 So the range function well this one is useful. 05:28.630 --> 05:34.360 You can just generate an array of numbers from 1 to 5. 05:34.390 --> 05:35.860 That's obviously an example. 05:35.860 --> 05:38.470 You can choose whatever numbers you want. 05:39.850 --> 05:42.940 So let's vardump this one. 05:44.110 --> 05:50.770 And also I'd like to make sure that we don't have the screen too cluttered. 05:50.770 --> 05:53.020 So I'm going to comment those out. 05:53.980 --> 05:55.420 So let's run it. 05:55.750 --> 05:58.150 This is our array of numbers. 05:58.150 --> 06:02.200 As you can see, it is indexed starting from zero. 06:04.090 --> 06:09.370 Then let's do something with this array so we can use some functions. 06:10.090 --> 06:14.530 So I think we've already had this example of squaring the numbers. 06:14.530 --> 06:16.720 But let's have it again. 06:16.720 --> 06:19.030 So we have array map function. 06:19.030 --> 06:23.950 Now this will return a new array and we can pass a callback to it. 06:23.950 --> 06:31.480 So we are passing an arrow function that will do something to every element from the array. 06:37.450 --> 06:39.640 So we square the number. 06:39.910 --> 06:44.860 And we also need to pass the array to this function. 06:45.490 --> 06:46.360 Okay. 06:46.360 --> 06:49.180 Now let's vardump the results. 06:52.630 --> 06:54.130 And let's run it. 06:55.810 --> 07:02.020 So that's the original one and that's the results array. 07:04.750 --> 07:05.380 All right. 07:05.410 --> 07:09.490 Now another one is an array filter. 07:10.750 --> 07:19.090 So let's create an array of even numbers and use array filter to only get the even numbers from either 07:19.090 --> 07:21.190 numbers or squared array. 07:21.250 --> 07:23.260 I'm going to go with numbers. 07:23.290 --> 07:30.850 Now as you can see, PHP is not really consistent with the order of arguments. 07:31.090 --> 07:38.590 So with array map the array came second with array filter it comes first. 07:39.370 --> 07:41.200 This is just how it is. 07:41.200 --> 07:43.690 Nothing we can do about this. 07:43.900 --> 07:44.380 Okay. 07:44.380 --> 07:46.990 Let's have an arrow function here. 07:47.020 --> 07:53.200 This is function n and I think we've seen that before. 07:53.200 --> 07:59.670 So we use the modulo operator and we get the remainder of dividing by two. 07:59.700 --> 08:04.260 If it happens to be zero, this is an even number. 08:04.890 --> 08:07.860 Never forget the semicolon. 08:09.690 --> 08:13.260 And why won't we vardump this? 08:13.260 --> 08:17.370 To see the results and all those functions. 08:17.400 --> 08:17.730 Array. 08:17.730 --> 08:18.300 Filter. 08:18.330 --> 08:19.350 Array map. 08:19.380 --> 08:27.000 They will produce new arrays, so they just don't modify the original array that you've passed to it. 08:27.030 --> 08:30.570 Typically this only happens with sorting. 08:30.570 --> 08:32.310 So let's run this one. 08:32.310 --> 08:36.300 And here we have it from the original numbers array. 08:36.330 --> 08:39.360 Only two and four are even numbers. 08:41.310 --> 08:41.550 Okay. 08:41.580 --> 08:45.120 Next up let's see an array reduce function. 08:45.120 --> 08:48.270 So this might be a tough one. 08:48.270 --> 08:51.630 So let's make sure you focus on this one. 08:52.320 --> 08:54.330 So we call array reduce. 08:54.330 --> 09:00.690 Now the goal of array reduce is to reduce the array to one single value. 09:01.920 --> 09:05.640 So in this case first argument would be the array. 09:06.120 --> 09:07.950 Next up would be a function. 09:07.950 --> 09:09.630 I'm going to add it in a second. 09:09.630 --> 09:13.560 And there is also a third argument which is the initial value. 09:13.590 --> 09:21.660 Since we want to reduce that the array to one single value, we also start with an initial value, which 09:21.690 --> 09:27.690 in this case is zero, because we want to calculate the sum of numbers. 09:27.690 --> 09:29.580 So we start with zero. 09:29.580 --> 09:34.530 And now it's important how the callback function looks like. 09:34.560 --> 09:38.100 Let me move every single argument into a separate line. 09:39.720 --> 09:42.870 So your function will receive two arguments. 09:42.870 --> 09:48.450 The first one is called carry and the second one is the element from the array. 09:48.480 --> 09:51.420 Now you don't have to call this argument carry. 09:51.420 --> 09:52.500 It's up to you. 09:52.500 --> 10:00.180 But this is how this is called in the array reduce function, which is not unique to PHP. 10:00.540 --> 10:06.540 And the way it works is we go over every single number from the array. 10:06.570 --> 10:10.650 So if we take a look in here we've got five of those. 10:10.860 --> 10:17.250 And you should return a single value from this callback. 10:17.280 --> 10:25.770 So in our case if we want to calculate the sum, we return the value that was carried from the previous 10:25.770 --> 10:30.120 run or the initial value of that was passed to array reduce. 10:30.120 --> 10:37.830 So this one, when this callback is called for the first time plus n okay. 10:37.830 --> 10:40.860 So with the first call we've got an initial value. 10:40.860 --> 10:43.050 So carry would be zero. 10:43.050 --> 10:45.270 And first element is one. 10:45.270 --> 10:47.280 So we return one from it. 10:47.280 --> 10:52.890 But on the second element of this number's array Carrie is now one. 10:52.890 --> 10:58.290 So we add 1 to 2 and you see where I'm going. 10:58.290 --> 11:00.060 So let's vardump this. 11:00.060 --> 11:05.760 And this also doesn't modify the original array. 11:05.880 --> 11:09.540 And the sum is 15. 11:12.360 --> 11:12.690 Okay. 11:12.690 --> 11:15.060 So now let's see something new. 11:15.300 --> 11:17.280 The array unpacking. 11:17.310 --> 11:21.990 I think this was only introduced in PHP 7.4. 11:22.650 --> 11:26.640 So I'm going to define a more numbers array. 11:26.910 --> 11:29.940 So array is always defined by square brackets. 11:29.940 --> 11:31.770 I'm going to add one value to it. 11:31.770 --> 11:35.610 And then I'm going to unpack the numbers array. 11:35.610 --> 11:39.030 And also I will add something at the end. 11:39.090 --> 11:46.050 So the way it works does a three dot operator before an array doesn't have to be variable. 11:46.050 --> 11:50.570 You can just add an array directly in here like that. 11:53.030 --> 12:00.290 So this operator in this case will just move all the elements from this numbers array into this more 12:00.290 --> 12:01.460 numbers array. 12:02.720 --> 12:04.220 Let's see this in practice. 12:04.220 --> 12:08.720 And I think everything would be clear what's happening in here. 12:10.700 --> 12:11.990 Let's run it right now. 12:11.990 --> 12:13.880 And this is our new array. 12:13.880 --> 12:21.920 So the element that I've added everything that was unpacked from numbers array and this one that we 12:21.920 --> 12:23.900 have added at the end. 12:24.080 --> 12:24.650 Okay. 12:24.680 --> 12:26.840 So this is array unpacking. 12:27.290 --> 12:27.560 Okay. 12:27.590 --> 12:31.610 So next up let's see array destructuring. 12:32.150 --> 12:34.220 So remember our fruits array. 12:34.250 --> 12:35.570 Let's use it. 12:36.140 --> 12:46.160 And using this assignment I want to get the first and second element of the arrays and assign them to 12:46.190 --> 12:47.570 a variable called first. 12:47.570 --> 12:49.940 And a variable called Second. 12:50.030 --> 12:53.450 So let's see what's the result of this. 12:55.970 --> 13:00.680 So this should be some fruits but I'm not sure which ones. 13:00.710 --> 13:01.190 Okay. 13:01.190 --> 13:04.910 So the value of first variable is apple. 13:05.030 --> 13:07.310 The value of second is banana. 13:07.310 --> 13:09.320 So they seem to be sorted. 13:09.350 --> 13:11.870 I can also skip elements. 13:11.870 --> 13:16.700 So uh sorry not here I can skip elements in here. 13:16.700 --> 13:22.160 So actually the variable second would contain the third element. 13:23.030 --> 13:24.830 So definitely not banana. 13:24.860 --> 13:27.770 Now this is orange okay. 13:28.220 --> 13:30.140 Anyway this is possible. 13:33.320 --> 13:33.830 Okay guys. 13:33.830 --> 13:39.200 So I was thinking about going through arrays in one go. 13:39.200 --> 13:41.600 But I think this would be too long. 13:41.600 --> 13:48.680 So let's have a short break and go back to more arrays in the next video.