1 00:00:01,170 --> 00:00:03,220 Let's challenge ourselves 2 00:00:03,220 --> 00:00:05,473 with Coding Challenge number two. 3 00:00:07,230 --> 00:00:09,260 And in this one, we're gonna continue 4 00:00:09,260 --> 00:00:12,130 with our football betting application. 5 00:00:12,130 --> 00:00:13,600 And let me start by saying 6 00:00:13,600 --> 00:00:16,920 that this challenge is actually a bit difficult. 7 00:00:16,920 --> 00:00:17,820 All right? 8 00:00:17,820 --> 00:00:19,580 But that is on purpose. 9 00:00:19,580 --> 00:00:22,450 So after all, it's called a challenge. 10 00:00:22,450 --> 00:00:24,930 And so you should really challenge yourself 11 00:00:24,930 --> 00:00:26,900 with these exercises. 12 00:00:26,900 --> 00:00:28,430 Otherwise it could be called 13 00:00:28,430 --> 00:00:31,580 a coding copy and paste, right? 14 00:00:31,580 --> 00:00:34,290 So please try your best to solve these. 15 00:00:34,290 --> 00:00:36,733 And you can try the problem solving framework 16 00:00:36,733 --> 00:00:38,950 that we talked about earlier. 17 00:00:38,950 --> 00:00:41,760 And of course you can also use Google MDN 18 00:00:41,760 --> 00:00:43,710 and so on and so forth. 19 00:00:43,710 --> 00:00:44,720 Okay. 20 00:00:44,720 --> 00:00:48,890 But with that out of the way, let's get into the exercises. 21 00:00:48,890 --> 00:00:53,470 And the first one is to loop over the game.scored array 22 00:00:53,470 --> 00:00:56,720 and then print each of the players to the console 23 00:00:56,720 --> 00:00:58,940 along with the goal number. 24 00:00:58,940 --> 00:01:00,533 So this one is not that hard. 25 00:01:01,520 --> 00:01:03,850 And so let's just... 26 00:01:04,839 --> 00:01:06,010 Yeah. 27 00:01:06,010 --> 00:01:08,260 So the object is down here, 28 00:01:08,260 --> 00:01:11,360 so we're gonna use the same object. All right? 29 00:01:11,360 --> 00:01:14,050 So this is the array that I was talking about. 30 00:01:14,050 --> 00:01:15,408 And so here, in this case, 31 00:01:15,408 --> 00:01:18,670 we should print "lewandowski" goal one, 32 00:01:18,670 --> 00:01:22,210 Then here goal two, "Gnarby", goal three "Lewandowski", 33 00:01:22,210 --> 00:01:24,397 and goal four, "Hummels". 34 00:01:26,734 --> 00:01:28,250 Okay. 35 00:01:28,250 --> 00:01:32,950 Then number two, use a loop to calculate the average odd 36 00:01:32,950 --> 00:01:35,060 and to log it to the console. 37 00:01:35,060 --> 00:01:38,380 And we already studied how to calculate averages. 38 00:01:38,380 --> 00:01:41,980 And so you can go check that out if you don't remember. 39 00:01:41,980 --> 00:01:46,100 And here you should actually directly use the object itself. 40 00:01:46,100 --> 00:01:49,610 So don't destruct the object first into variables 41 00:01:49,610 --> 00:01:52,350 and then use that to calculate the average, 42 00:01:52,350 --> 00:01:55,720 but instead really calculate the average of the elements 43 00:01:55,720 --> 00:01:58,570 in the object, okay? 44 00:01:58,570 --> 00:02:01,830 Then number three, I want you to print the three odds 45 00:02:01,830 --> 00:02:05,970 to the console and do that in a nice formatted way, 46 00:02:05,970 --> 00:02:07,393 like you can see it here. 47 00:02:09,970 --> 00:02:13,420 Now here, You're not allowed to hard-code 48 00:02:13,420 --> 00:02:14,920 the names of the teams. 49 00:02:14,920 --> 00:02:15,753 Alright. 50 00:02:15,753 --> 00:02:19,453 So instead get them directly from the game object itself. 51 00:02:21,180 --> 00:02:23,380 Now of course you're except for draw 52 00:02:23,380 --> 00:02:26,640 because that's nowhere in the game object. 53 00:02:26,640 --> 00:02:30,430 So as a hint, I have fear that the odds 54 00:02:30,430 --> 00:02:34,250 and the game objects have the exact same property names. 55 00:02:34,250 --> 00:02:36,540 And so you can use that knowledge maybe 56 00:02:36,540 --> 00:02:38,923 to get the name of the teams here. 57 00:02:40,690 --> 00:02:44,630 So these are the three exercises for this challenge, 58 00:02:44,630 --> 00:02:47,290 but then I also have a bonus. 59 00:02:47,290 --> 00:02:49,690 Now, let me just tell you that I will not solve 60 00:02:49,690 --> 00:02:51,720 this bonus question in this video 61 00:02:51,720 --> 00:02:54,740 because it would take me a little bit too long 62 00:02:54,740 --> 00:02:56,350 but I will still put the solution 63 00:02:56,350 --> 00:02:58,750 in the final code of this section, 64 00:02:58,750 --> 00:03:00,840 so in the GitHub repository, 65 00:03:00,840 --> 00:03:02,680 so you can check out the solution there 66 00:03:02,680 --> 00:03:05,770 if you attempt to do this bonus. 67 00:03:05,770 --> 00:03:07,610 So this one is really hard. 68 00:03:07,610 --> 00:03:10,550 And what I want you to do 69 00:03:10,550 --> 00:03:13,430 is to create an object called scores, 70 00:03:13,430 --> 00:03:15,950 which will contain the name of the players 71 00:03:15,950 --> 00:03:19,200 who scored as properties, 72 00:03:19,200 --> 00:03:22,410 and so Gnarby, Hummels, and Lewandowski were the players 73 00:03:22,410 --> 00:03:24,290 who scored in this game. 74 00:03:24,290 --> 00:03:26,980 And as a value for each of the properties 75 00:03:26,980 --> 00:03:29,790 we want the number of goals. 76 00:03:29,790 --> 00:03:31,050 Alright. 77 00:03:31,050 --> 00:03:33,930 So this means Lewandowski scored two goals 78 00:03:33,930 --> 00:03:37,700 and the other two players scored just one goal each. 79 00:03:37,700 --> 00:03:40,800 So this is a little bit difficult again 80 00:03:40,800 --> 00:03:42,530 but you can do it. 81 00:03:42,530 --> 00:03:45,190 Well at least with some research 82 00:03:45,190 --> 00:03:47,960 and with some reviewing of all the material 83 00:03:47,960 --> 00:03:50,170 of the course so far. 84 00:03:50,170 --> 00:03:53,170 Anyway, good luck with this challenge. 85 00:03:53,170 --> 00:03:54,170 Take your time. 86 00:03:54,170 --> 00:03:55,370 And I'll see you once 87 00:03:55,370 --> 00:03:56,203 you're ready. 88 00:04:00,350 --> 00:04:01,183 All right. 89 00:04:02,210 --> 00:04:07,210 Hopefully you did at least one or two of these exercises. 90 00:04:08,060 --> 00:04:10,820 And so here it goes my solution. 91 00:04:10,820 --> 00:04:13,050 And keep in mind once more that my solution 92 00:04:13,050 --> 00:04:16,430 might be different from yours, but that's totally okay. 93 00:04:16,430 --> 00:04:19,840 As long as yours produces the same result. 94 00:04:19,840 --> 00:04:23,790 So here, the goal is to score on the scored array, 95 00:04:23,790 --> 00:04:26,920 and print all of the players to the console. 96 00:04:26,920 --> 00:04:31,920 So const, and let's again fix that later, 97 00:04:32,850 --> 00:04:37,850 and then of game.scored. 98 00:04:38,110 --> 00:04:40,423 And now we actually want the entries. 99 00:04:42,640 --> 00:04:43,473 All right. 100 00:04:43,473 --> 00:04:46,730 And we want the indexes because we also want 101 00:04:46,730 --> 00:04:47,910 the number of the goal. 102 00:04:47,910 --> 00:04:48,743 Remember? 103 00:04:48,743 --> 00:04:50,773 So goal one, two, three, and four. 104 00:04:51,880 --> 00:04:55,164 Okay. And so entries will give us that. 105 00:04:55,164 --> 00:04:58,170 And so now we just need to re-structure that 106 00:04:58,170 --> 00:05:01,183 into the index and then the player. 107 00:05:04,190 --> 00:05:07,630 Okay. Actually we don't even need to curly braces. 108 00:05:07,630 --> 00:05:11,310 Let's just say, console.log and then Goal, 109 00:05:15,350 --> 00:05:17,070 then the index plus one. 110 00:05:17,070 --> 00:05:19,513 So that it starts at goal number one, 111 00:05:21,132 --> 00:05:23,433 and then simply the player. 112 00:05:24,500 --> 00:05:25,523 Let's take a look. 113 00:05:26,530 --> 00:05:28,570 Oh, and now we have the problem here 114 00:05:28,570 --> 00:05:32,003 that I'm accessing game before it is initialized. 115 00:05:33,010 --> 00:05:35,483 And so the problem is that the game is down here. 116 00:05:36,560 --> 00:05:39,760 So I'll have to take this game object now 117 00:05:39,760 --> 00:05:41,113 to that other challenge. 118 00:05:42,480 --> 00:05:46,773 So let's just cut it from here and put it here. 119 00:05:49,620 --> 00:05:51,080 So now it should work. 120 00:05:51,080 --> 00:05:53,260 And indeed we get the four goals 121 00:05:53,260 --> 00:05:55,070 nicely printed to the console 122 00:05:56,000 --> 00:05:58,633 exactly in the order in which they appear here. 123 00:06:01,890 --> 00:06:04,130 Alright, next one. 124 00:06:04,130 --> 00:06:08,000 And it is one we have to calculate the average odd. 125 00:06:08,000 --> 00:06:12,000 So the average basically of these three numbers here. 126 00:06:12,000 --> 00:06:16,340 So what we're gonna do is to loop over this object here 127 00:06:16,340 --> 00:06:19,490 and simply add all of these three values together 128 00:06:19,490 --> 00:06:23,920 and then finally divide them by the number of elements here. 129 00:06:23,920 --> 00:06:26,950 And so that's how you calculate an average. 130 00:06:26,950 --> 00:06:31,950 And so we start by creating the average and set it to zero. 131 00:06:34,220 --> 00:06:37,403 And so again, we already did that before, I believe. 132 00:06:38,410 --> 00:06:39,710 And so now we can loop 133 00:06:39,710 --> 00:06:43,073 over the object such as I explained it to you before. 134 00:06:45,320 --> 00:06:50,320 const odd of, and now what do we actually want? 135 00:06:51,030 --> 00:06:54,770 Do we want the keys or the values or both? 136 00:06:54,770 --> 00:06:57,270 Well, in this case, we are really just interested 137 00:06:57,270 --> 00:06:59,373 in the values, right? 138 00:07:00,230 --> 00:07:03,760 And so this Object.values will give us an array 139 00:07:03,760 --> 00:07:06,563 essentially containing these three values. 140 00:07:08,740 --> 00:07:13,740 So we need to say game.odds. 141 00:07:15,260 --> 00:07:16,093 Okay. 142 00:07:16,093 --> 00:07:17,210 And now in each iteration, 143 00:07:17,210 --> 00:07:20,560 we will simply add these odds to the average. 144 00:07:20,560 --> 00:07:21,490 So that then in the end, 145 00:07:21,490 --> 00:07:26,363 we can divide it by the length of this object.values array. 146 00:07:27,580 --> 00:07:32,547 So let's do that, plus equal the current odd, 147 00:07:34,921 --> 00:07:38,613 and then finally average, average divided equal, 148 00:07:41,470 --> 00:07:46,470 and so this is a new one, by object.values, game.odds, 149 00:07:52,319 --> 00:07:54,683 and then let's log it to the console. 150 00:07:56,880 --> 00:07:59,313 So this one here means basically, 151 00:07:59,313 --> 00:08:03,593 average is equal average divided by this here. 152 00:08:04,830 --> 00:08:06,840 And this is actually the same as up here, 153 00:08:06,840 --> 00:08:10,253 so that's refactor it into let's say, 154 00:08:14,480 --> 00:08:19,480 simply odds, and then let's use that here. 155 00:08:20,900 --> 00:08:21,733 Odds, 156 00:08:23,010 --> 00:08:24,023 and odds. 157 00:08:26,930 --> 00:08:28,470 And we have a problem. 158 00:08:28,470 --> 00:08:30,844 So let's do some debugging here. 159 00:08:30,844 --> 00:08:34,540 I will start by taking a look at the average 160 00:08:34,540 --> 00:08:37,423 after it is computed here in the array. 161 00:08:39,200 --> 00:08:42,220 So average, oh. 162 00:08:42,220 --> 00:08:43,820 So here we have a number 163 00:08:43,820 --> 00:08:47,190 which means that something is wrong here in the division. 164 00:08:47,190 --> 00:08:48,580 Right. 165 00:08:48,580 --> 00:08:52,793 And I see it's because we need to write odds.length. 166 00:08:54,020 --> 00:08:58,160 Okay. And so then it will be the number three in this case. 167 00:08:58,160 --> 00:09:01,050 So before I was dividing by the entire array 168 00:09:01,050 --> 00:09:03,280 and that doesn't make any sense. 169 00:09:03,280 --> 00:09:06,773 And so now we should see something close to four here. 170 00:09:07,760 --> 00:09:11,560 Yeah. So 3.7 essentially. 171 00:09:11,560 --> 00:09:13,463 And so that's our result. 172 00:09:14,740 --> 00:09:15,850 Okay. 173 00:09:15,850 --> 00:09:18,050 And you can go over to this code here again, 174 00:09:19,120 --> 00:09:21,470 if you need to understand that even further, 175 00:09:21,470 --> 00:09:25,013 but now let's move on here to Exercise number three. 176 00:09:26,300 --> 00:09:29,080 And this time the goal is to print basically 177 00:09:29,080 --> 00:09:32,210 the content of the object to the console. 178 00:09:32,210 --> 00:09:34,101 So we're gonna loop over that. 179 00:09:34,101 --> 00:09:38,420 And again, I will first say what we need here actually. 180 00:09:38,420 --> 00:09:42,420 So we want to print both the team and the odd, 181 00:09:42,420 --> 00:09:44,590 so we need the entire object. 182 00:09:44,590 --> 00:09:48,010 And so just as we learned in a previous lecture, 183 00:09:48,010 --> 00:09:53,010 we use object.entries of game.odds. 184 00:09:58,650 --> 00:10:02,590 Okay. And so we know that we get an array of arrays, 185 00:10:02,590 --> 00:10:07,590 which in each position will have both the team and the odd. 186 00:10:07,780 --> 00:10:08,613 All right. 187 00:10:08,613 --> 00:10:13,083 So let's say team and odd. 188 00:10:15,200 --> 00:10:16,033 All right. 189 00:10:16,033 --> 00:10:19,190 And so here it is us who defined the variable name 190 00:10:19,190 --> 00:10:21,350 because it is now an array. 191 00:10:21,350 --> 00:10:23,763 So we don't have to match any property names. 192 00:10:24,630 --> 00:10:28,190 And let's start by simply logging both to the console 193 00:10:28,190 --> 00:10:30,793 team and odd. 194 00:10:33,180 --> 00:10:34,013 Okay. 195 00:10:34,013 --> 00:10:36,780 And so indeed, we already have that kind of working. 196 00:10:36,780 --> 00:10:38,660 We already have the team here 197 00:10:38,660 --> 00:10:41,663 and we have the three odd values. 198 00:10:42,740 --> 00:10:44,940 Now what we want to do is to create a string 199 00:10:46,360 --> 00:10:48,113 like this. 200 00:10:49,350 --> 00:10:50,590 let's actually copy this. 201 00:10:50,590 --> 00:10:52,123 So we know what we have to do. 202 00:11:00,500 --> 00:11:02,587 And by the way, here, notice again, 203 00:11:02,587 --> 00:11:04,930 what I explained to you in the last lecture, 204 00:11:04,930 --> 00:11:08,480 how in the array we use the entries method 205 00:11:08,480 --> 00:11:10,310 to get the entries of the array, 206 00:11:10,310 --> 00:11:13,900 but in the object we have to use object.entries 207 00:11:13,900 --> 00:11:16,090 and then pass into the function, 208 00:11:16,090 --> 00:11:19,080 the object that we are interested in. 209 00:11:19,080 --> 00:11:20,957 So that's fundamentally difference. 210 00:11:20,957 --> 00:11:22,633 So keep that in mind. 211 00:11:25,100 --> 00:11:29,220 Okay. So here, we now want to build a string like that. 212 00:11:29,220 --> 00:11:34,220 So odd of victory Bayern Munich, 213 00:11:34,880 --> 00:11:37,660 draw or victory Borussia Dortmund. 214 00:11:37,660 --> 00:11:39,920 And so here, we're gonna need some more logic. 215 00:11:39,920 --> 00:11:41,693 Let's just put here some dots. 216 00:11:42,890 --> 00:11:45,080 And now, now here the odd. 217 00:11:45,080 --> 00:11:46,850 So the odd is the easy part. 218 00:11:46,850 --> 00:11:48,713 So we have that one already finished. 219 00:11:50,180 --> 00:11:53,113 But now here we need some more complex logic. 220 00:11:54,050 --> 00:11:57,253 And actually let's create this part of the string. 221 00:11:58,250 --> 00:12:01,310 So like victory Bayern Munich, or Borrusia Dortmund 222 00:12:01,310 --> 00:12:04,403 or draw, let's create it here in a separate value. 223 00:12:08,720 --> 00:12:10,680 So let's call this one teamString. 224 00:12:12,530 --> 00:12:14,050 And so here what I'm gonna use 225 00:12:14,050 --> 00:12:16,570 is to use the ternery operator. 226 00:12:16,570 --> 00:12:17,600 Okay. 227 00:12:17,600 --> 00:12:21,570 So I will say that if the team here is x, 228 00:12:21,570 --> 00:12:22,530 like we have a it here, 229 00:12:22,530 --> 00:12:25,090 then the string should become draw. 230 00:12:25,090 --> 00:12:27,563 And so that will then create this here. 231 00:12:29,180 --> 00:12:34,180 So team equals x then the result should be draw. 232 00:12:37,170 --> 00:12:42,130 But if not, then we need the team name itself. 233 00:12:42,130 --> 00:12:44,680 So how will we get that? 234 00:12:44,680 --> 00:12:47,303 And remember, there was a hint about this. 235 00:12:48,400 --> 00:12:49,970 So note how the odds 236 00:12:49,970 --> 00:12:53,610 and the game objects have the same property names. 237 00:12:53,610 --> 00:12:56,700 And indeed here we have team one, team two, 238 00:12:56,700 --> 00:13:00,140 and here we have team one and team two as well. 239 00:13:00,140 --> 00:13:02,653 And so here are the team names. 240 00:13:03,970 --> 00:13:07,060 And so let's now get these team names 241 00:13:07,060 --> 00:13:10,163 using these keys that we already have here. 242 00:13:13,405 --> 00:13:15,520 So we want to string victory. 243 00:13:21,660 --> 00:13:25,483 And then we go to the game object and team. 244 00:13:27,400 --> 00:13:28,363 Let's check. 245 00:13:29,580 --> 00:13:32,313 Now I know of course we need to put that string here. 246 00:13:34,270 --> 00:13:39,270 So teamString and it works beautiful. 247 00:13:41,330 --> 00:13:43,750 So let's just recap this part here. 248 00:13:43,750 --> 00:13:46,010 So here we go into the game, 249 00:13:46,010 --> 00:13:48,470 which is the entire game object 250 00:13:48,470 --> 00:13:51,230 and we take the property team. 251 00:13:51,230 --> 00:13:54,810 But team is already this property name here, right? 252 00:13:54,810 --> 00:13:56,610 So it's team one or team two. 253 00:13:56,610 --> 00:13:59,580 And so then we take that to read the property 254 00:13:59,580 --> 00:14:02,003 with the same name from the game object. 255 00:14:03,400 --> 00:14:06,733 And so therefore we get Bayern Munich and Borussia Dortmund. 256 00:14:08,430 --> 00:14:09,361 Okay. Great. 257 00:14:09,361 --> 00:14:12,460 So this one was a little bit more tough 258 00:14:12,460 --> 00:14:15,320 but we managed to do it in the end. 259 00:14:15,320 --> 00:14:18,120 Now, again, I will not create the solution 260 00:14:18,120 --> 00:14:20,620 for the bonus but you can always find it 261 00:14:20,620 --> 00:14:23,720 in the final code of this section. 262 00:14:23,720 --> 00:14:25,100 And with that being said, 263 00:14:25,100 --> 00:14:28,143 let's now go back to learning some more JavaScript.