1 00:00:01,290 --> 00:00:05,633 And now, it's time for coding challenge number three. 2 00:00:07,380 --> 00:00:08,970 And we are still working 3 00:00:08,970 --> 00:00:11,700 on our football betting application. 4 00:00:11,700 --> 00:00:15,850 Now this time, we have this map down here. 5 00:00:15,850 --> 00:00:19,590 So this one, which contains all the events that happened 6 00:00:19,590 --> 00:00:21,360 during the game. 7 00:00:21,360 --> 00:00:24,370 So the values here are the events themselves, 8 00:00:24,370 --> 00:00:27,680 for example, a goal or a substitution, 9 00:00:27,680 --> 00:00:31,833 and the keys are the minutes, in which the event occurs. 10 00:00:32,790 --> 00:00:37,270 And just notice, that a football game has 90 minutes, 11 00:00:37,270 --> 00:00:39,180 plus some extra time. 12 00:00:39,180 --> 00:00:41,650 So this might be a little bit over 90, 13 00:00:41,650 --> 00:00:43,980 but usually it's always 90 minutes, 14 00:00:43,980 --> 00:00:47,563 in case you're not familiar with this beautiful game. 15 00:00:48,630 --> 00:00:53,020 Anyway, your tasks are to create an array called events, 16 00:00:53,020 --> 00:00:55,410 which will contain all the different game events 17 00:00:55,410 --> 00:00:57,830 that happened during this game. 18 00:00:57,830 --> 00:01:00,983 And that means no duplicates in that array. 19 00:01:01,960 --> 00:01:03,970 Now, after the game has finished, 20 00:01:03,970 --> 00:01:08,970 it was found that the yellow card from minute 64 was unfair. 21 00:01:09,050 --> 00:01:12,810 So please just remove this event from the log. 22 00:01:12,810 --> 00:01:16,260 Next up print dis string to the console. 23 00:01:16,260 --> 00:01:19,000 An event happened on average every nine minutes. 24 00:01:19,000 --> 00:01:23,890 And of course, your task is to calculate this nine minutes, 25 00:01:23,890 --> 00:01:27,473 keeping in mind, that a game has 90 minutes. 26 00:01:28,440 --> 00:01:31,380 Finally, loop over the events, 27 00:01:31,380 --> 00:01:33,320 and then log into the console. 28 00:01:33,320 --> 00:01:36,180 And what's tricky about this, is that you should mark 29 00:01:36,180 --> 00:01:39,010 whether they happened in the first half of the game, 30 00:01:39,010 --> 00:01:40,740 or the second half. 31 00:01:40,740 --> 00:01:43,130 And the second half means, 32 00:01:43,130 --> 00:01:46,003 that it happened after 45 minutes. 33 00:01:46,990 --> 00:01:49,123 So it should look something like this. 34 00:01:50,380 --> 00:01:53,380 So I believe that this challenge is a little bit easier 35 00:01:53,380 --> 00:01:54,760 than the previous one, 36 00:01:54,760 --> 00:01:57,570 and so hopefully you can manage to complete 37 00:01:57,570 --> 00:01:59,320 all of these four tasks. 38 00:01:59,320 --> 00:02:01,463 So I'll see you once you're done. 39 00:02:05,670 --> 00:02:09,160 So, I hope that was fun. 40 00:02:09,160 --> 00:02:12,540 So let's get started immediately with the solution here. 41 00:02:12,540 --> 00:02:16,380 So we should create an array called events, 42 00:02:16,380 --> 00:02:18,720 with the unique events. 43 00:02:18,720 --> 00:02:23,720 So basically, that's the unique values of all of these here. 44 00:02:24,460 --> 00:02:27,100 Now, what are these values here? 45 00:02:27,100 --> 00:02:31,270 They are essentially the values of this map, right? 46 00:02:31,270 --> 00:02:34,660 So, what I'm saying, is that they are 47 00:02:34,660 --> 00:02:39,660 in gameEvents.values. 48 00:02:40,020 --> 00:02:42,010 And we learned about this one 49 00:02:42,010 --> 00:02:44,893 kind of by the end of the last video. 50 00:02:46,870 --> 00:02:49,070 So let's comment out this one here. 51 00:02:49,070 --> 00:02:52,820 And so indeed, we see that this is what contains 52 00:02:52,820 --> 00:02:55,733 the values that we are interested in. 53 00:02:57,260 --> 00:02:58,093 Alright. 54 00:02:59,130 --> 00:03:02,713 So, let's say gameEvents.values, 55 00:03:05,280 --> 00:03:07,510 and this is our starting point, 56 00:03:07,510 --> 00:03:09,870 and now to get the unique values here, 57 00:03:09,870 --> 00:03:14,690 we basically need to create a set, out of this, right? 58 00:03:14,690 --> 00:03:17,183 That's the main use case of sets. 59 00:03:18,580 --> 00:03:23,480 So, new set, but this alone is not going to be enough, 60 00:03:23,480 --> 00:03:24,963 but let's still take a look, 61 00:03:27,860 --> 00:03:28,923 at this for now, 62 00:03:30,760 --> 00:03:32,370 and beautiful. 63 00:03:32,370 --> 00:03:34,770 So, indeed we have a set with the only 64 00:03:34,770 --> 00:03:37,450 four events that happened. 65 00:03:37,450 --> 00:03:40,890 So, there were only goals, substitutions yellow cards 66 00:03:40,890 --> 00:03:42,083 and red cards. 67 00:03:43,030 --> 00:03:47,330 And now to convert us to an array, we do adjust like before. 68 00:03:47,330 --> 00:03:49,090 Create a new array, 69 00:03:49,090 --> 00:03:53,270 and a spread operator to unpack this set, 70 00:03:53,270 --> 00:03:54,863 and then we are done. 71 00:03:56,960 --> 00:04:01,310 Next up, this one is the easiest one, 72 00:04:01,310 --> 00:04:05,963 so it tells us to delete the event from minute 64. 73 00:04:06,900 --> 00:04:09,090 So that's very easy. 74 00:04:09,090 --> 00:04:13,460 So gameEvents.delete, 75 00:04:13,460 --> 00:04:17,530 and now all we have to do is to use that exact key, 76 00:04:17,530 --> 00:04:20,350 and then that event will be gone. 77 00:04:20,350 --> 00:04:24,343 Great. The next one is just as easy I believe. 78 00:04:26,550 --> 00:04:28,903 So let's just grab this from here. 79 00:04:33,757 --> 00:04:38,257 And now we just need to calculate this actual average. 80 00:04:39,150 --> 00:04:40,463 And how do we do that? 81 00:04:41,640 --> 00:04:46,640 So basically, to say that an event happened every X minutes, 82 00:04:47,160 --> 00:04:51,320 we simply need to divide the number of events by 90 minutes. 83 00:04:51,320 --> 00:04:52,923 So the duration of the game. 84 00:04:54,050 --> 00:04:54,910 So, we see here 85 00:04:54,910 --> 00:04:59,910 that we have three, six, nine, eleven events. 86 00:05:00,110 --> 00:05:02,993 So, how can we count that programmatically? 87 00:05:04,120 --> 00:05:07,840 Well, for that we have gameEvents.size, remember? 88 00:05:11,510 --> 00:05:15,150 And now we just divide that by 90, 89 00:05:15,150 --> 00:05:18,730 and with that, we get this weird number 90 00:05:18,730 --> 00:05:22,480 and that's because in fact we need the opposite. 91 00:05:22,480 --> 00:05:23,660 So we need to say 92 00:05:23,660 --> 00:05:28,660 90 minutes divided by how many events there happened, 93 00:05:29,620 --> 00:05:31,640 to say that on average, 94 00:05:31,640 --> 00:05:33,663 something happened every nine minutes. 95 00:05:35,040 --> 00:05:38,050 Now, if we want it to be really specific, 96 00:05:38,050 --> 00:05:41,630 then this game actually lasted 92 minutes. 97 00:05:41,630 --> 00:05:44,183 So, how do we get that value? 98 00:05:46,560 --> 00:05:48,770 So this is just a bonus, Okay? 99 00:05:48,770 --> 00:05:52,310 I didn't expect you to do this one. 100 00:05:52,310 --> 00:05:55,150 So this 92, is essentially the last 101 00:05:55,150 --> 00:05:57,193 of the keys of the map. 102 00:05:58,450 --> 00:06:00,560 I'm sold. Let's get the keys. 103 00:06:00,560 --> 00:06:05,490 So, that's gameEvents.keys. 104 00:06:05,490 --> 00:06:09,033 And as always, we need to convert this to an array. 105 00:06:11,500 --> 00:06:13,943 So, using all the tools that we already learned. 106 00:06:16,040 --> 00:06:17,393 So just to make sure, 107 00:06:19,580 --> 00:06:21,270 indeed it is. 108 00:06:21,270 --> 00:06:23,880 And now we want the last value. 109 00:06:23,880 --> 00:06:26,270 And how can we get the last value? 110 00:06:26,270 --> 00:06:28,210 Do you remember that? 111 00:06:28,210 --> 00:06:31,180 Well, we can use the pop method. 112 00:06:31,180 --> 00:06:34,440 And in the past, we mainly used the pop method, 113 00:06:34,440 --> 00:06:37,540 to simply delete the last element of the array. 114 00:06:37,540 --> 00:06:39,690 But also, back then I told you, 115 00:06:39,690 --> 00:06:42,743 that it also returns, that deleted array. 116 00:06:43,880 --> 00:06:46,280 Or actually that deleted element. 117 00:06:46,280 --> 00:06:49,860 And so, here we can take the advantage of that. 118 00:06:49,860 --> 00:06:52,500 So, this here is an array now, 119 00:06:52,500 --> 00:06:54,883 and so on that, we can call pop. 120 00:06:56,340 --> 00:06:59,640 And so that will take, the last element out of the array 121 00:06:59,640 --> 00:07:00,693 and give it to us. 122 00:07:01,640 --> 00:07:03,100 So that's 92. 123 00:07:03,100 --> 00:07:05,253 And so to make this really accurate, 124 00:07:07,180 --> 00:07:10,293 here we can now say, time. 125 00:07:12,890 --> 00:07:16,710 Okay. And so this, is even better right now, 126 00:07:16,710 --> 00:07:19,850 but again, this is just kind of a bonus 127 00:07:19,850 --> 00:07:23,090 just to show you some more nice little tricks. 128 00:07:23,090 --> 00:07:27,013 Anyway. Now our goal is to loop through the object, 129 00:07:28,510 --> 00:07:30,073 or actually through the map. 130 00:07:34,130 --> 00:07:37,683 And so this is pretty standard now at this point. 131 00:07:40,740 --> 00:07:42,573 Here we are missing the off. 132 00:07:43,500 --> 00:07:46,810 So just like we did in the last video, 133 00:07:46,810 --> 00:07:50,880 and now all we need to do, is to figure out the half. 134 00:07:50,880 --> 00:07:53,823 So if it's the first half, or the second half. 135 00:07:56,050 --> 00:07:59,490 So, what we want to lock to the console is this. 136 00:07:59,490 --> 00:08:02,163 And then so, either a first or second half, 137 00:08:06,230 --> 00:08:07,523 and then the minute, 138 00:08:08,370 --> 00:08:09,593 I believe, let's see. 139 00:08:10,580 --> 00:08:14,423 Yeah. So, the minute and then colon, and then the event. 140 00:08:15,800 --> 00:08:18,860 So let's actually make these here more specific, 141 00:08:18,860 --> 00:08:21,710 so a minute and event. 142 00:08:21,710 --> 00:08:23,760 So that makes it easier to read the code. 143 00:08:25,910 --> 00:08:29,313 So minute and event. 144 00:08:30,280 --> 00:08:33,803 And now here, let's just again, create an external variable, 145 00:08:34,730 --> 00:08:36,380 which I'm going to call the Half. 146 00:08:41,170 --> 00:08:44,210 And let's use the turnery operator here again, 147 00:08:44,210 --> 00:08:48,683 so if the minute is below or equal 45, 148 00:08:50,520 --> 00:08:54,300 then it is the first, 149 00:08:54,300 --> 00:08:57,393 otherwise it's the second, 150 00:08:59,030 --> 00:09:00,680 and that's it. 151 00:09:00,680 --> 00:09:04,753 And, that worked just fine once again. Okay. 152 00:09:07,130 --> 00:09:09,620 So, I hope that made sense, 153 00:09:09,620 --> 00:09:13,010 in case it didn't, then it's always just analyze the code, 154 00:09:13,010 --> 00:09:17,970 or you can also just ask some questions in the Q and A area. 155 00:09:17,970 --> 00:09:21,630 Anyway, we're now almost done with this section. 156 00:09:21,630 --> 00:09:25,550 Next up, all we have left to do is to work with strengths, 157 00:09:25,550 --> 00:09:28,990 which is also a really nice and really interesting topic 158 00:09:28,990 --> 00:09:31,930 that we need in JavaScript all the time. 159 00:09:31,930 --> 00:09:34,783 So make sure to follow me there, right away.