WEBVTT 1 00:00:01.310 --> 00:00:04.780 Welcome back to the first coding challenge 2 00:00:04.780 --> 00:00:06.573 of the arrays section. 3 00:00:08.410 --> 00:00:13.380 And in this one, Julia and Kate are doing a study on dogs. 4 00:00:13.380 --> 00:00:17.960 So each of them asked five dog owners about their dog's age 5 00:00:17.960 --> 00:00:21.830 and then they stored that data into an array. 6 00:00:21.830 --> 00:00:25.070 And that's one array for each of them. 7 00:00:25.070 --> 00:00:26.420 All right? 8 00:00:26.420 --> 00:00:29.370 And in this study, they are interested in knowing 9 00:00:29.370 --> 00:00:33.620 whether each of the dogs is an adult or a puppy. 10 00:00:33.620 --> 00:00:36.610 And the rule is that a dog is an adult 11 00:00:36.610 --> 00:00:39.430 if it is at least three years old, 12 00:00:39.430 --> 00:00:43.123 and it's a puppy if it's less than three years old. 13 00:00:44.060 --> 00:00:46.280 And by the way, the test data here, 14 00:00:46.280 --> 00:00:50.000 so the arrays for it is down here. 15 00:00:50.000 --> 00:00:52.700 So test data one and two. 16 00:00:52.700 --> 00:00:54.100 All right? 17 00:00:54.100 --> 00:00:58.570 So, your task is to create a function called check dogs, 18 00:00:58.570 --> 00:01:00.900 which accepts these two arrays 19 00:01:00.900 --> 00:01:02.573 and does the following things. 20 00:01:03.930 --> 00:01:08.530 So first, Julia found out that the owners of the first 21 00:01:08.530 --> 00:01:13.530 and the last two dogs do actually have cats and not dogs. 22 00:01:13.650 --> 00:01:15.430 So here, what I want you to do 23 00:01:15.430 --> 00:01:18.910 is to create a shallow copy of Julia's array 24 00:01:18.910 --> 00:01:23.040 and then remove the cat ages from the copied array. 25 00:01:23.040 --> 00:01:26.040 And you should copy it because it's a bad practice 26 00:01:26.040 --> 00:01:29.653 to mutate the parameters or the arguments of a function. 27 00:01:30.750 --> 00:01:32.580 Then second, create an array 28 00:01:32.580 --> 00:01:35.950 with both Julia's and Kate's data. 29 00:01:35.950 --> 00:01:39.280 So for Julia, of course, the corrected data. 30 00:01:39.280 --> 00:01:40.940 And then for each of the dogs, 31 00:01:40.940 --> 00:01:44.700 simply log to the console whether it is an adult 32 00:01:44.700 --> 00:01:46.780 with a string like this 33 00:01:46.780 --> 00:01:50.160 or a puppy and then with a string like this. 34 00:01:50.160 --> 00:01:52.008 And that's, of course, according to the rules 35 00:01:52.008 --> 00:01:53.830 in the beginning. 36 00:01:53.830 --> 00:01:57.920 And then, just run this function for both test data sets. 37 00:01:57.920 --> 00:01:59.430 And that's it. 38 00:01:59.430 --> 00:02:01.980 So all you need to do is to use the tools 39 00:02:01.980 --> 00:02:04.990 from all the lectures in this section so far 40 00:02:04.990 --> 00:02:08.830 and then I think you will be fine solving this on your own. 41 00:02:08.830 --> 00:02:11.260 So this is really all about using the tools 42 00:02:11.260 --> 00:02:13.270 that we already learned before 43 00:02:13.270 --> 00:02:16.743 and there's not a lot of new thinking to do here. 44 00:02:17.600 --> 00:02:19.650 So I hope you manage to do this one. 45 00:02:19.650 --> 00:02:21.703 And I see you back here in a second. 46 00:02:25.520 --> 00:02:26.353 All right. 47 00:02:28.860 --> 00:02:32.880 So hopefully, you did this just fine without any problems 48 00:02:34.880 --> 00:02:39.120 but I will anyway write my solution here 49 00:02:39.120 --> 00:02:41.760 and explain what I am doing. 50 00:02:41.760 --> 00:02:45.510 So, we accept the dogs from Julia 51 00:02:45.510 --> 00:02:48.143 and the dogs from Kate. 52 00:02:51.550 --> 00:02:55.240 And we will call this with the test data. 53 00:02:55.240 --> 00:02:57.570 And so, Julia's data is this 54 00:02:57.570 --> 00:03:01.530 and there's not a need to store them in separate variables. 55 00:03:01.530 --> 00:03:03.603 I will just call the function like this. 56 00:03:07.770 --> 00:03:08.930 All right? 57 00:03:08.930 --> 00:03:12.963 And now we should create a shallow copy of dogs Julia, 58 00:03:14.720 --> 00:03:17.623 so that we can then remove some elements from there. 59 00:03:18.840 --> 00:03:21.323 So dogsJuliaCorrected.slice 60 00:03:23.816 --> 00:03:27.150 So dogsJuliaCorrected.slice 61 00:03:28.090 --> 00:03:30.660 and so I'm using here the method 62 00:03:30.660 --> 00:03:33.290 and not the spread operator. 63 00:03:33.290 --> 00:03:36.880 And now, I will simply remove some elements from there. 64 00:03:36.880 --> 00:03:41.440 So dogsJuliaCorrected.splice 65 00:03:43.030 --> 00:03:47.110 and so, it tells us that the first 66 00:03:47.110 --> 00:03:51.773 and the last two dogs are not valid basically. 67 00:03:52.700 --> 00:03:57.140 So, the first is element number zero 68 00:03:57.140 --> 00:03:59.343 and then we want to remove one. 69 00:04:00.760 --> 00:04:02.093 So that's the first part. 70 00:04:02.980 --> 00:04:07.900 And then dogsJuliaCorrected.splice 71 00:04:08.900 --> 00:04:11.333 and then the last two, which is minus two. 72 00:04:12.200 --> 00:04:13.033 Okay? 73 00:04:13.970 --> 00:04:17.268 So, let's take a look here simply at 74 00:04:17.268 --> 00:04:22.040 dogsJuliaCorrected just to see 75 00:04:22.040 --> 00:04:24.193 if this is correct actually. 76 00:04:25.470 --> 00:04:27.670 So we need the console now. 77 00:04:27.670 --> 00:04:32.020 And so this was or beginning data and indeed, 78 00:04:32.020 --> 00:04:35.930 the first and the last two are done here. 79 00:04:35.930 --> 00:04:37.260 All right? 80 00:04:37.260 --> 00:04:39.760 Now, of course, you could have also done this 81 00:04:39.760 --> 00:04:41.250 in a different way, 82 00:04:41.250 --> 00:04:43.830 which is to simply copy the correct data 83 00:04:43.830 --> 00:04:46.653 from the original using the slice method. 84 00:04:48.180 --> 00:04:51.317 So something like this: dogsJulia.slice, 85 00:04:52.838 --> 00:04:55.960 So something like this: dogsJulia.slice, 86 00:04:55.960 --> 00:04:58.450 so starting from the second one 87 00:04:58.450 --> 00:05:00.623 and then all the way to the third one. 88 00:05:02.710 --> 00:05:06.270 Okay, and so this would give us the exact same result 89 00:05:06.270 --> 00:05:10.630 but in this case, I just wanted to use the splice method. 90 00:05:10.630 --> 00:05:14.850 And, in fact, I wanted you to use the splice method as well 91 00:05:14.850 --> 00:05:17.763 and that's why I gave you that task like that. 92 00:05:19.140 --> 00:05:22.270 Anyway, we don't need this here anymore. 93 00:05:22.270 --> 00:05:26.663 Let's now simply create a new variable with both these dogs. 94 00:05:27.600 --> 00:05:29.510 So simply calling it dogs. 95 00:05:29.510 --> 00:05:32.000 And again, we could use the spread operator here 96 00:05:32.000 --> 00:05:34.180 which I actually prefer 97 00:05:34.180 --> 00:05:37.010 but since we are in the arrays section here, 98 00:05:37.010 --> 00:05:39.283 let's do everything with array methods. 99 00:05:41.110 --> 00:05:44.080 So that's the concat method, remember? 100 00:05:44.080 --> 00:05:45.440 And then we want to join 101 00:05:46.350 --> 00:05:50.023 the corrected Julia dogs with dogs Kate. 102 00:05:54.380 --> 00:05:56.473 So always a good idea to check. 103 00:05:57.340 --> 00:05:59.933 And yeah, that's correct. 104 00:06:02.170 --> 00:06:03.120 All right? 105 00:06:03.120 --> 00:06:05.810 And so, all we have to do now is 106 00:06:06.890 --> 00:06:09.270 basically create this string. 107 00:06:09.270 --> 00:06:10.993 Let me just copy this string. 108 00:06:12.500 --> 00:06:16.920 And so, looping over this array is now an easy task. 109 00:06:16.920 --> 00:06:18.370 Hopefully. 110 00:06:18.370 --> 00:06:20.237 So dogs.forEach 111 00:06:22.420 --> 00:06:24.250 then the callback function 112 00:06:24.250 --> 00:06:25.410 and one more time, 113 00:06:25.410 --> 00:06:29.993 we need actually the current element and also the index. 114 00:06:31.240 --> 00:06:34.760 And that's because here is the number. 115 00:06:34.760 --> 00:06:38.763 So dog number one and it's going to go all the way to seven. 116 00:06:40.070 --> 00:06:42.483 And so, let's check out our rule. 117 00:06:43.340 --> 00:06:47.893 So, a dog is an adult if he is at least three years old. 118 00:06:51.290 --> 00:06:56.203 So if dog is greater equal three, 119 00:06:57.720 --> 00:07:02.483 then log a string like this. 120 00:07:08.890 --> 00:07:11.313 So here is the index plus one. 121 00:07:15.505 --> 00:07:19.960 Here goes the dog itself 122 00:07:19.960 --> 00:07:21.040 and then else 123 00:07:24.260 --> 00:07:25.403 is still a puppy. 124 00:07:30.470 --> 00:07:32.573 And here we need just this. 125 00:07:34.110 --> 00:07:36.673 And, I think, with this we are good. 126 00:07:37.720 --> 00:07:38.793 Just remove this. 127 00:07:40.510 --> 00:07:45.030 And yes, dog number one is five years old, 128 00:07:45.030 --> 00:07:47.050 so it's still an adult. 129 00:07:47.050 --> 00:07:51.200 Number two is two years old, so still a puppy. 130 00:07:51.200 --> 00:07:53.480 This is again a puppy with one year old 131 00:07:55.140 --> 00:07:59.450 and so, yeah, that's the correct solution. 132 00:07:59.450 --> 00:08:02.423 Now let's just do it for this test data here. 133 00:08:05.295 --> 00:08:07.653 Gonna duplicate this one. 134 00:08:14.380 --> 00:08:16.180 Let's just comment out the first one 135 00:08:18.270 --> 00:08:21.280 and okay, here we only have one puppy 136 00:08:21.280 --> 00:08:24.110 which is the one before the last. 137 00:08:24.110 --> 00:08:26.640 And so this one is correct as well. 138 00:08:26.640 --> 00:08:28.933 And so, challenge completed.