1 00:00:00,300 --> 00:00:05,300 So let me show you my solution to this challenge 2 00:00:05,430 --> 00:00:09,330 which I hope of course, you were able to do on your own. 3 00:00:09,330 --> 00:00:12,540 So I'm gonna start with the calc average function, 4 00:00:12,540 --> 00:00:14,163 as in number one. 5 00:00:15,150 --> 00:00:17,880 And remember that this should be an arrow function, 6 00:00:17,880 --> 00:00:20,250 and it will receive three values, 7 00:00:20,250 --> 00:00:24,600 so that it can calculate the average of these three numbers. 8 00:00:24,600 --> 00:00:27,240 And here, I'm actually just gonna call the three numbers, 9 00:00:27,240 --> 00:00:32,189 A, B, and C, because again, 10 00:00:32,189 --> 00:00:35,280 this is supposed to be just a generic function 11 00:00:35,280 --> 00:00:38,850 which can calculate averages of any three numbers. 12 00:00:38,850 --> 00:00:40,830 It doesn't have to be any scores. 13 00:00:40,830 --> 00:00:44,670 And so, A, B, C, are just generic, variable names, 14 00:00:44,670 --> 00:00:47,070 but of course, it's totally okay 15 00:00:47,070 --> 00:00:50,073 if you used more specific variable names. 16 00:00:51,840 --> 00:00:54,180 So adding all the three numbers together, 17 00:00:54,180 --> 00:00:56,340 and then dividing by three. 18 00:00:56,340 --> 00:00:57,810 So this one is nothing new. 19 00:00:57,810 --> 00:01:00,540 This was just to basically test your knowledge 20 00:01:00,540 --> 00:01:03,360 of the syntax of the arrow function. 21 00:01:03,360 --> 00:01:05,099 So what's important to notice here 22 00:01:05,099 --> 00:01:06,990 is that we need the parenthesis here 23 00:01:06,990 --> 00:01:09,600 because we have multiple parameters, 24 00:01:09,600 --> 00:01:12,840 but then here, we only really have this line of code. 25 00:01:12,840 --> 00:01:16,770 And so therefore, we don't need to even write the return. 26 00:01:16,770 --> 00:01:20,700 This value gets automatically returned from the function. 27 00:01:20,700 --> 00:01:24,810 And now, let's just test it out before we move any further. 28 00:01:24,810 --> 00:01:29,810 So calc average and then let's just use some random numbers 29 00:01:30,390 --> 00:01:32,880 because here we know that 30 00:01:32,880 --> 00:01:36,630 this is supposed to be four, right? 31 00:01:36,630 --> 00:01:38,100 So we have 3, 4, 5. 32 00:01:38,100 --> 00:01:41,280 And so the middle one here is the average 33 00:01:41,280 --> 00:01:43,023 between these three, 34 00:01:44,610 --> 00:01:46,230 and indeed it is. 35 00:01:46,230 --> 00:01:48,630 And so, we know that our function works. 36 00:01:48,630 --> 00:01:51,570 And so, we can move on to point number two 37 00:01:51,570 --> 00:01:53,760 which is to use the function to calculate 38 00:01:53,760 --> 00:01:55,923 the average for both teams. 39 00:01:57,420 --> 00:02:01,320 So let's say, 40 00:02:01,320 --> 00:02:06,320 score dolphins is equal to calc average. 41 00:02:08,160 --> 00:02:10,350 And now we passed in the specific arguments 42 00:02:10,350 --> 00:02:13,950 for the three parameters, A, B, and C. 43 00:02:13,950 --> 00:02:16,890 And so, for test data one, which is this, 44 00:02:16,890 --> 00:02:20,370 so let me actually write that here, test one. 45 00:02:20,370 --> 00:02:25,370 So for the dolphins, we pass in the values 44, 23, and 71. 46 00:02:28,560 --> 00:02:32,220 Then for the koalas, it works the same way. 47 00:02:32,220 --> 00:02:36,540 So score, koalas equals calc average, 48 00:02:36,540 --> 00:02:40,593 and now, we have 65, 54, 49 00:02:41,880 --> 00:02:43,293 and 49. 50 00:02:44,370 --> 00:02:47,613 So nice reusable function right here. 51 00:02:48,660 --> 00:02:50,970 And so, having this function, we don't need 52 00:02:50,970 --> 00:02:54,450 to calculate it here manually every single time. 53 00:02:54,450 --> 00:02:56,103 So that's really great. 54 00:02:56,940 --> 00:03:00,870 So we can really appreciate the fact that again, 55 00:03:00,870 --> 00:03:04,890 a function is really like a machine in some sense. 56 00:03:04,890 --> 00:03:07,530 So it doesn't care where the inputs come from 57 00:03:07,530 --> 00:03:09,360 and where they go. 58 00:03:09,360 --> 00:03:12,930 All it does is to calculate the average of three numbers, 59 00:03:12,930 --> 00:03:16,230 no matter if it scores or heights of people, 60 00:03:16,230 --> 00:03:18,900 or money, or whatever it is. 61 00:03:18,900 --> 00:03:21,540 So this function really is kind of isolated 62 00:03:21,540 --> 00:03:23,730 from the rest of the code here. 63 00:03:23,730 --> 00:03:25,320 It's a standalone function 64 00:03:25,320 --> 00:03:29,010 that we can then use for our own purposes. 65 00:03:29,010 --> 00:03:31,230 And that might sound pretty obvious, 66 00:03:31,230 --> 00:03:32,580 but it's actually important 67 00:03:32,580 --> 00:03:36,720 that you really internalize this aspect of functions. 68 00:03:36,720 --> 00:03:39,870 Only then can you really start to see the potential 69 00:03:39,870 --> 00:03:43,380 for functions everywhere in your coat. 70 00:03:43,380 --> 00:03:48,380 Anyway, with that being said, let's now log these values 71 00:03:48,600 --> 00:03:53,600 to the console 'cause I always like to see what I'm doing. 72 00:03:54,000 --> 00:03:56,373 So this part is of course not mandatory, 73 00:03:57,300 --> 00:04:00,120 but it's also nice to be able to know these scores, 74 00:04:00,120 --> 00:04:02,280 so that we know if the logic that we're 75 00:04:02,280 --> 00:04:05,163 gonna implement next is working correctly. 76 00:04:06,030 --> 00:04:08,730 So we see that in this case, 77 00:04:08,730 --> 00:04:11,490 the koalas have a score that is higher 78 00:04:11,490 --> 00:04:14,940 than one of the dolphins, but it's not double. 79 00:04:14,940 --> 00:04:17,550 And so, we already know that in this case, 80 00:04:17,550 --> 00:04:20,459 no team should be able to win, 81 00:04:20,459 --> 00:04:23,433 but let's now actually implement that functionality. 82 00:04:24,420 --> 00:04:27,270 So that's the function check winner. 83 00:04:27,270 --> 00:04:29,520 And so, it takes the average dolphins 84 00:04:29,520 --> 00:04:33,417 and average koalas parameters, okay? 85 00:04:33,417 --> 00:04:36,450 And then it locks the winner to the console. 86 00:04:36,450 --> 00:04:38,253 So let's do that. 87 00:04:39,510 --> 00:04:42,993 And once more, it's no problem if you did this differently. 88 00:04:45,120 --> 00:04:47,823 If you made it work, then it's great. 89 00:04:49,350 --> 00:04:54,350 So average dolphins and average koalas. 90 00:04:57,660 --> 00:04:59,850 And now, all we need to do is to check 91 00:04:59,850 --> 00:05:01,410 whether the dolphins won 92 00:05:01,410 --> 00:05:06,090 or the koalas won, or if no one won basically. 93 00:05:06,090 --> 00:05:08,880 So when do the dolphins win? 94 00:05:08,880 --> 00:05:11,750 Well, they win if they have doubled the points 95 00:05:11,750 --> 00:05:13,680 of the koalas right? 96 00:05:13,680 --> 00:05:14,730 That's the condition. 97 00:05:16,260 --> 00:05:18,960 So again, a team only wins if it has 98 00:05:18,960 --> 00:05:22,410 at least double the average score of the other team. 99 00:05:22,410 --> 00:05:25,980 And so, that's why I told you here in this hint 100 00:05:25,980 --> 00:05:27,783 that this is how we check for that. 101 00:05:28,890 --> 00:05:32,760 So A has doubled the amount of point of B 102 00:05:32,760 --> 00:05:35,583 if A is greater than two times B. 103 00:05:37,140 --> 00:05:39,123 So let's do that. 104 00:05:40,920 --> 00:05:45,000 So average dolphins greater or equal 105 00:05:45,000 --> 00:05:50,000 to two times the average koalas. 106 00:05:50,820 --> 00:05:53,883 And in this case, we log to the console. 107 00:05:57,660 --> 00:06:01,110 Dolphins win the trophy. 108 00:06:01,110 --> 00:06:02,883 So let's use an emoji here, again, 109 00:06:03,720 --> 00:06:06,240 but you don't need of course to do that. 110 00:06:06,240 --> 00:06:07,413 So it's already here. 111 00:06:08,640 --> 00:06:12,390 And now, it also told us to put the points. 112 00:06:12,390 --> 00:06:17,353 So for example, 30 versus 13. 113 00:06:19,260 --> 00:06:22,410 So both points with the versus in between. 114 00:06:22,410 --> 00:06:27,410 So that's average dolphins versus average koalas. 115 00:06:32,820 --> 00:06:35,760 So you see that here, we are also practicing all 116 00:06:35,760 --> 00:06:39,360 the other skills that we already acquired before, 117 00:06:39,360 --> 00:06:41,973 especially in the previous section, right? 118 00:06:43,620 --> 00:06:46,980 Okay. And now here, we gonna just need to do the opposite. 119 00:06:46,980 --> 00:06:51,540 So else if and now 120 00:06:51,540 --> 00:06:55,320 if the koalas have at least, 121 00:06:55,320 --> 00:06:58,380 so that's basically what this one here means. 122 00:06:58,380 --> 00:07:01,770 So greater equal is basically at least. 123 00:07:01,770 --> 00:07:05,260 So if average koalas have at least double the points 124 00:07:06,300 --> 00:07:11,300 of the dolphins, then the koalas win. 125 00:07:11,700 --> 00:07:14,433 So let's just grab this one from here, 126 00:07:15,780 --> 00:07:16,713 koalas, 127 00:07:19,650 --> 00:07:20,640 average koalas, 128 00:07:20,640 --> 00:07:24,003 and then average dolphins, 129 00:07:25,500 --> 00:07:26,883 average, yes. 130 00:07:27,840 --> 00:07:31,410 All right, and now, in any other case, 131 00:07:31,410 --> 00:07:33,990 we say that no one wins. 132 00:07:33,990 --> 00:07:36,273 So I think that's also said in the rules. 133 00:07:37,470 --> 00:07:39,360 Yeah, that's number five. 134 00:07:39,360 --> 00:07:42,480 I think I even forgot to tell you this one, 135 00:07:42,480 --> 00:07:44,250 but hopefully you read it. 136 00:07:44,250 --> 00:07:49,250 So you should ignore draws in this exercise this time. 137 00:07:50,220 --> 00:07:51,810 So if none of these is true, 138 00:07:51,810 --> 00:07:53,763 we simply say that no team wins. 139 00:07:57,030 --> 00:08:00,153 No team wins. 140 00:08:01,770 --> 00:08:02,760 Okay. 141 00:08:02,760 --> 00:08:06,663 And now, all we need to do is to call this function here. 142 00:08:07,560 --> 00:08:11,520 So check winner, and we will do that 143 00:08:11,520 --> 00:08:13,570 with score dolphins 144 00:08:14,610 --> 00:08:18,063 and score koalas. 145 00:08:19,140 --> 00:08:21,930 Okay? So let's recap. 146 00:08:21,930 --> 00:08:23,160 We calculated the score 147 00:08:23,160 --> 00:08:27,090 of the dolphins up here and of the koalas as well. 148 00:08:27,090 --> 00:08:32,090 And now, we call the check winner function here, okay? 149 00:08:32,100 --> 00:08:33,600 And we use as arguments, 150 00:08:33,600 --> 00:08:36,150 the scores that we calculated before. 151 00:08:36,150 --> 00:08:39,669 And then, score dolphins will become average dolphins 152 00:08:41,159 --> 00:08:42,330 here in this function 153 00:08:42,330 --> 00:08:44,760 because that's the name of the parameter. 154 00:08:44,760 --> 00:08:46,950 And I see that I misspelled this, 155 00:08:46,950 --> 00:08:50,310 and so, now I can use that command D that I talked 156 00:08:50,310 --> 00:08:53,370 to you about before, so I can select all of them. 157 00:08:53,370 --> 00:08:54,750 So command D, command D, 158 00:08:54,750 --> 00:08:58,230 command D, command D, and now I can use all 159 00:08:58,230 --> 00:09:00,660 of these cursors here at the same time. 160 00:09:00,660 --> 00:09:01,713 So dolphins. 161 00:09:03,810 --> 00:09:06,390 You see? I inserted the P in all 162 00:09:06,390 --> 00:09:08,943 of the variable names everywhere. 163 00:09:10,980 --> 00:09:12,330 Now, all right? 164 00:09:12,330 --> 00:09:15,630 And so, now this parameter name here gets used 165 00:09:15,630 --> 00:09:17,940 for all these calculations. 166 00:09:17,940 --> 00:09:22,170 And again, originally, this value comes basically from here, 167 00:09:22,170 --> 00:09:26,040 from calculating the average of these three scores. 168 00:09:26,040 --> 00:09:30,180 So this average gets stored here, then we use it here, 169 00:09:30,180 --> 00:09:34,020 and then it gets basically transferred to average dolphins, 170 00:09:34,020 --> 00:09:36,423 and is then used everywhere in this function. 171 00:09:37,680 --> 00:09:40,080 Okay? So let's now test. 172 00:09:40,080 --> 00:09:44,580 And as we expected, no team wins because this team here, 173 00:09:44,580 --> 00:09:48,510 even though it has more than the dolphins, it's not double. 174 00:09:48,510 --> 00:09:50,493 And so therefore, they do not win. 175 00:09:51,360 --> 00:09:54,660 Now of course, what is also important to mention here 176 00:09:54,660 --> 00:09:57,960 is that this check winner function here 177 00:09:57,960 --> 00:10:00,390 is also completely independent 178 00:10:00,390 --> 00:10:04,410 of these score values that we calculated earlier. 179 00:10:04,410 --> 00:10:07,440 So here, we can simply call this function 180 00:10:07,440 --> 00:10:09,510 with completely different values. 181 00:10:09,510 --> 00:10:12,810 So the function doesn't care where these values come from, 182 00:10:12,810 --> 00:10:16,560 so where average dolphins and average koalas come from. 183 00:10:16,560 --> 00:10:18,240 It's a standalone function, 184 00:10:18,240 --> 00:10:21,360 and it doesn't care at all where these values came from. 185 00:10:21,360 --> 00:10:23,560 We can just plug in some random numbers here 186 00:10:25,140 --> 00:10:29,040 and then call it, and let's use a smaller number here. 187 00:10:29,040 --> 00:10:32,310 Okay, so just so that the average dolphin here 188 00:10:32,310 --> 00:10:35,223 is actually more than double of the average koalas. 189 00:10:36,120 --> 00:10:38,490 So if you run this now, 190 00:10:38,490 --> 00:10:43,490 then we see that the dolphins win with 576 versus 111. 191 00:10:44,760 --> 00:10:46,530 And so, that's exactly the numbers 192 00:10:46,530 --> 00:10:50,400 that we plugged in in here, okay? 193 00:10:50,400 --> 00:10:53,190 So once more, it's important to keep in mind 194 00:10:53,190 --> 00:10:56,310 that these functions are all independent from another. 195 00:10:56,310 --> 00:10:59,010 We just happen to call check winner here 196 00:10:59,010 --> 00:11:01,500 with these values that we calculated before, 197 00:11:01,500 --> 00:11:03,600 but it's not mandatory to do that. 198 00:11:03,600 --> 00:11:06,810 Any other values will work just as well. 199 00:11:06,810 --> 00:11:08,193 And so, we prove that here. 200 00:11:09,210 --> 00:11:13,020 Anyway, now, let's use test data 2. 201 00:11:13,020 --> 00:11:14,460 And actually what I'm gonna do is 202 00:11:14,460 --> 00:11:17,850 to reassign these two scores here. 203 00:11:17,850 --> 00:11:21,840 So we calculate them first, then we call check winner, 204 00:11:21,840 --> 00:11:24,240 and then I'm going to recalculate them 205 00:11:24,240 --> 00:11:26,670 and call check winner again. 206 00:11:26,670 --> 00:11:30,240 So what I mean by saying that is that these need 207 00:11:30,240 --> 00:11:34,470 to be let variables, so that we can reassign them. 208 00:11:34,470 --> 00:11:39,060 Remember that cons values cannot be mutated. 209 00:11:39,060 --> 00:11:43,710 They cannot be changed, and so they need to be let. 210 00:11:43,710 --> 00:11:46,740 And then here, of course, we need to get rid of 211 00:11:46,740 --> 00:11:50,550 that let because we do not want to create new variables. 212 00:11:50,550 --> 00:11:52,260 We just want to overwrite. 213 00:11:52,260 --> 00:11:55,893 So we want to reassign the values that we had earlier. 214 00:11:57,510 --> 00:12:00,863 So this time, the values are 85, 54, and 41. 215 00:12:07,710 --> 00:12:12,710 85, 54, and 41, 216 00:12:12,840 --> 00:12:14,880 and I hope that's correct, 217 00:12:14,880 --> 00:12:17,553 and then 40 koalas. 218 00:12:18,840 --> 00:12:22,413 We have 23, 34, and 27. 219 00:12:24,240 --> 00:12:29,053 So that's 23, 34, and 27. 220 00:12:31,650 --> 00:12:33,753 Let's lock these actually also. 221 00:12:34,710 --> 00:12:39,420 And then simply call check winner again. 222 00:12:39,420 --> 00:12:41,010 And now, with the new values 223 00:12:41,010 --> 00:12:43,590 of score dolphins and score koalas, 224 00:12:43,590 --> 00:12:46,833 they'll be just reassigned, okay? 225 00:12:47,820 --> 00:12:50,013 So let's see. 226 00:12:51,060 --> 00:12:53,070 And now, the dolphins have an average score 227 00:12:53,070 --> 00:12:55,800 of 60 and the koalas of 28. 228 00:12:55,800 --> 00:13:00,800 And so now, the dolphins win with 60 versus 28, 229 00:13:01,350 --> 00:13:03,450 so that's a close call. 230 00:13:03,450 --> 00:13:05,670 So if the koalas had three more points, 231 00:13:05,670 --> 00:13:07,230 then no one would win, 232 00:13:07,230 --> 00:13:09,633 but the dolphins managed to do it. 233 00:13:10,950 --> 00:13:15,950 Great. So I hope that this all made sense to you, 234 00:13:16,530 --> 00:13:18,720 and I know it is probably still 235 00:13:18,720 --> 00:13:21,390 a bit confusing at this point. 236 00:13:21,390 --> 00:13:23,520 And if you did some things differently, 237 00:13:23,520 --> 00:13:26,700 well then once more, that is completely okay. 238 00:13:26,700 --> 00:13:28,080 It just means you're developing 239 00:13:28,080 --> 00:13:31,290 your own coding style over time. 240 00:13:31,290 --> 00:13:34,110 For example, here with the average scores, 241 00:13:34,110 --> 00:13:37,440 of course, you could have created new variables down here 242 00:13:37,440 --> 00:13:39,510 for the test data 2. 243 00:13:39,510 --> 00:13:41,100 So that's just one of many things 244 00:13:41,100 --> 00:13:42,930 that you could have done differently 245 00:13:42,930 --> 00:13:44,400 which are perfectly fine. 246 00:13:44,400 --> 00:13:48,300 As long as your results are the same, you are good to go, 247 00:13:48,300 --> 00:13:51,390 so take some time and review this lecture. 248 00:13:51,390 --> 00:13:54,600 Remember that you can check out my final code also 249 00:13:54,600 --> 00:13:58,560 in the final folder, in the GitHub repo, 250 00:13:58,560 --> 00:14:02,790 and then you're ready to move on to our next big topic 251 00:14:02,790 --> 00:14:05,820 in the section, which is gonna be a race. 252 00:14:05,820 --> 00:14:07,833 So I hope to see you there soon.