WEBVTT 00:00.500 --> 00:00.830 Okay. 00:00.830 --> 00:03.080 Now let's define those two arrays. 00:03.080 --> 00:06.020 Those will be just a set of numbers. 00:06.020 --> 00:10.880 And we're going to calculate the intersection of those two arrays. 00:10.880 --> 00:16.370 So the common elements and then the differences between those two arrays. 00:16.550 --> 00:21.410 First to get the intersection we call array intersect. 00:22.070 --> 00:24.350 And we pass those two variables. 00:24.350 --> 00:32.630 Now with intersection the order you pass the arrays does not matter because the common elements set 00:32.660 --> 00:35.090 would be always the same. 00:36.440 --> 00:43.280 Now there is also an array div function which is used to find the differences. 00:43.280 --> 00:53.720 So if I pass set one and set two, this means that I would like to see all the elements that are present 00:53.720 --> 01:02.640 in set one, but are not present in set two if I invert the order, this will actually give me a different 01:02.640 --> 01:12.540 result, because here I'm interested in elements that are in the set two but are not in set one, and 01:12.840 --> 01:16.050 those are a little bit different. 01:16.050 --> 01:18.090 They don't overlap. 01:19.530 --> 01:27.210 So first if we run that we can see that for the intersection we've got the same results. 01:27.210 --> 01:28.560 This makes sense. 01:28.560 --> 01:35.460 The common elements would always be the same but with the different elements. 01:36.120 --> 01:38.310 First we've got one and two. 01:38.340 --> 01:40.410 These are not present in this set. 01:40.410 --> 01:45.750 And if we invert the order of parameters we've got six and seven. 01:46.590 --> 01:51.480 So this makes sense that those numbers are not present in the first set. 01:53.490 --> 01:53.790 Okay. 01:53.790 --> 01:55.830 Now keys and values. 01:55.830 --> 02:01.210 So let's go back to this associative array we've defined at the top. 02:02.170 --> 02:09.130 And in PHP, you've got a way to just get all the keys and all the values of a specific associative 02:09.130 --> 02:12.100 array, which would produce a new array. 02:12.430 --> 02:14.140 So that's pretty simple. 02:14.140 --> 02:16.600 You do it using functions. 02:17.290 --> 02:20.320 First we've got array keys. 02:21.010 --> 02:23.470 This will just give us all the keys. 02:25.840 --> 02:33.880 And then we've got values which we retrieve using array values function. 02:35.410 --> 02:38.800 Now this is actually quite useful. 02:39.730 --> 02:42.550 So let me dump both. 02:46.030 --> 02:48.040 So here is the result of that. 02:48.040 --> 02:52.660 And those two functions are actually pretty handy. 02:52.840 --> 03:00.170 For example with the keys I can use that to label the table headers. 03:00.170 --> 03:13.130 If I would like to present the data in some kind of a table so I can get the keys, but then I can capitalize 03:13.130 --> 03:14.660 the first letter. 03:15.140 --> 03:17.360 So I've got array keys here. 03:17.360 --> 03:20.240 Maybe let me show you another example. 03:20.240 --> 03:23.150 So I can do array map. 03:25.730 --> 03:37.550 Then with every key I'm going to do you see first key and pass the array of keys to it. 03:39.830 --> 03:42.140 And let me run that again. 03:42.920 --> 03:48.620 And now I've got nicely formatted labels or table headers. 03:51.530 --> 03:54.320 So next up we've associative arrays. 03:54.320 --> 03:54.340 forays. 03:54.340 --> 03:58.090 You often might want to check if a key exists. 04:00.580 --> 04:04.240 So for that we also will use a function. 04:04.240 --> 04:05.830 This is called array. 04:05.860 --> 04:07.540 Key exists. 04:08.440 --> 04:13.000 So let's see if the name exists inside the associative array. 04:13.720 --> 04:17.710 Well we can already see that that is true. 04:18.070 --> 04:26.320 And another thing is to check if a value exists in an array that's not limited to associative arrays, 04:26.320 --> 04:33.730 because we can check for values in both types of arrays, whether associative or indexed. 04:34.780 --> 04:37.600 So we've got just one element that's John. 04:37.600 --> 04:40.690 So I expect both to return. 04:40.690 --> 04:41.560 True. 04:41.950 --> 04:44.920 Yeah I've missed the array here. 04:44.920 --> 04:46.420 That would make sense. 04:46.420 --> 04:50.680 To specify in which array I would like to check for a value. 04:50.710 --> 04:52.900 As you see both has returned. 04:52.940 --> 04:53.720 True. 04:55.940 --> 04:59.180 So next up, something we've seen already. 04:59.180 --> 05:04.070 But let's just remind you of this in context of the arrays. 05:04.280 --> 05:08.480 So this would be converting arrays to strings. 05:08.510 --> 05:15.650 This also is something that you're gonna use a lot, especially when importing or exporting data. 05:15.680 --> 05:18.410 The functions called implode. 05:18.530 --> 05:27.530 And you can just add a separator that will be added between all the elements of your array. 05:27.560 --> 05:29.750 So we've got this fruits. 05:30.860 --> 05:36.530 And the other side of this function is explode. 05:39.050 --> 05:41.150 So I can use explode. 05:43.310 --> 05:45.260 Past the separator as well. 05:45.260 --> 05:54.690 And this would convert a string to an array where Just this characters will be used to separate the 05:54.690 --> 05:56.160 specific elements. 05:57.630 --> 06:04.710 Now let me vardump the fruit string and back to array. 06:06.990 --> 06:09.900 So first we've created this string from an array. 06:09.900 --> 06:15.180 And then from the string we've created we converted that back to an array. 06:18.330 --> 06:18.630 Okay. 06:18.630 --> 06:22.740 Now let's see how can we merge the arrays. 06:23.400 --> 06:27.060 So first there is an array merge function. 06:27.060 --> 06:33.510 And let's first call it on the indexed arrays those two sets of numbers. 06:37.410 --> 06:42.870 So when I call it we get an array of ten elements. 06:43.140 --> 06:51.640 So it seems that array merge is just adding elements from this array and elements from the second array 06:51.640 --> 06:54.670 without really giving it much thought. 06:55.450 --> 07:01.510 Okay, now let's see an array merge example with our associative array. 07:03.910 --> 07:05.860 So this would be associative array. 07:05.860 --> 07:12.010 And this should be just this data with the name country etc.. 07:12.010 --> 07:14.320 And let me pass another array here. 07:14.440 --> 07:22.780 Now I know that this array contains a country key because I've added it and it contained USA. 07:22.810 --> 07:25.780 Let me change that to Germany. 07:26.620 --> 07:33.640 And first let me also output this array so we can see if anything has happened. 07:35.950 --> 07:38.110 So that's the original array. 07:38.830 --> 07:40.360 The country is USA. 07:40.360 --> 07:46.630 And in the resulting array from array merge the country is Germany. 07:46.660 --> 07:56.780 So in associative arrays, keys are taken into account, and if a key exists in the first array and 07:56.780 --> 08:00.350 in the second one, it will be overwritten. 08:00.350 --> 08:08.690 So the original keys from this first array will be overwritten if they are present in the second array. 08:10.340 --> 08:16.100 Okay, let me comment this out or remove it because there is also a union operator. 08:16.100 --> 08:18.650 That's just a plus sign. 08:21.890 --> 08:26.000 So let me call this without array merge. 08:28.760 --> 08:30.140 Just like this. 08:31.520 --> 08:39.290 And then let's also see what will happen in case of an associative array if I try to do the same. 08:44.360 --> 08:44.630 Okay. 08:44.630 --> 08:46.770 So here we've got the results. 08:47.430 --> 08:52.020 So with the plus operator, we've got this. 08:52.020 --> 08:56.040 This seems like we only have elements from the first array. 08:56.070 --> 08:57.660 I'm going to go back to this. 08:58.830 --> 09:08.220 And here with the associative array we can see that the country was not replaced and we still see USA. 09:08.250 --> 09:13.080 So let me explain how the union operator works on the arrays. 09:13.890 --> 09:18.720 So this union operator with arrays, it's based on keys. 09:18.720 --> 09:20.220 And the way it works. 09:20.220 --> 09:24.990 If there is a key in the original array it won't be modified. 09:24.990 --> 09:33.030 And the elements from the second array will only be added if they have a unique key. 09:33.330 --> 09:41.670 So since those both are indexed arrays, their keys are actually numbers from 0 to 4. 09:41.700 --> 09:49.210 Both have five elements, and since the keys are the same in both of them, we only see the elements 09:49.210 --> 09:56.560 from the first one, because the second array has the same indexes, the same numbers, thus nothing 09:56.560 --> 09:57.850 was modified. 09:58.540 --> 10:01.060 Now here we. 10:01.090 --> 10:03.430 We have added, let's call it. 10:03.460 --> 10:09.370 We have added an array which has a key that is already present in this original array. 10:09.400 --> 10:12.550 That's country was it was also. 10:12.730 --> 10:17.980 Well the resulting array did not have the country modified. 10:18.220 --> 10:26.770 Now if I would use a key that's not present in this first array instead. 10:27.460 --> 10:29.020 And let's see what will happen. 10:29.020 --> 10:33.190 Well then it would be added to this array. 10:33.310 --> 10:34.270 Okay. 10:34.270 --> 10:37.390 So let's have one more example. 10:37.870 --> 10:46.170 Let's just unpack both arrays into a new array using the spreading operator. 10:47.130 --> 10:48.750 So we do three dots. 10:48.780 --> 10:49.920 Three dots here. 10:49.920 --> 10:53.730 And there goes a comma, not a plus sign. 10:54.390 --> 10:56.940 Let's do the same right here. 10:59.670 --> 11:05.400 So there is not a plus sign but instead the spread operator. 11:07.410 --> 11:10.650 And let's see results here. 11:13.500 --> 11:17.700 So with the numbers we can see that this works like a right. 11:20.490 --> 11:25.830 So with the numbers we can see the result is like with the array merge function. 11:25.830 --> 11:29.520 Those elements were just added into the new array. 11:31.140 --> 11:33.780 And here with the associative array. 11:33.780 --> 11:39.000 Well let's change that back to country and run it again. 11:40.500 --> 11:43.390 So this also behaved like a ray merge. 11:43.420 --> 11:48.790 The country was replaced with the value from the second array. 11:51.250 --> 11:54.070 Okay, now let me comment out those results. 11:54.070 --> 11:57.970 And again let's rerun this. 11:57.970 --> 12:03.490 So here we've got an array with ten elements because we are just adding elements from first and the 12:03.490 --> 12:04.330 second array. 12:04.360 --> 12:08.470 Now if you'd like only have the unique ones. 12:09.190 --> 12:15.460 There is an array unique function to which we can pass the results of merge. 12:15.460 --> 12:20.290 And this now has only seven unique elements. 12:21.580 --> 12:32.740 Then if you just want a part of this, there is an array slice to which you pass, maybe set one, then 12:32.740 --> 12:34.450 you pass the starting index. 12:34.450 --> 12:37.120 Maybe that will be one and the amount of elements. 12:37.150 --> 12:38.920 Let's go with three. 12:39.890 --> 12:43.640 So you only get a slice of the array. 12:44.870 --> 12:54.530 And the final example is if you'd like to find something in an array, let's say you would like to get 12:54.530 --> 12:56.600 the index of an element. 12:57.230 --> 13:00.110 You can use an array search. 13:00.500 --> 13:05.420 So in the fruits array I like to search for banana. 13:06.110 --> 13:11.060 And I should get the index of this element in that array. 13:11.840 --> 13:15.800 So in case of fruits this is the second fruit vase. 13:15.830 --> 13:18.170 I get the index of one. 13:18.860 --> 13:19.250 Okay. 13:19.280 --> 13:21.800 So we've played a bit of arrays. 13:21.800 --> 13:30.950 Obviously there is always so much more information and so much more examples we can do, but I think 13:30.950 --> 13:38.270 this should really give you a solid foundations as the most important array functions and features were 13:38.270 --> 13:38.960 covered.