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These are the user uploaded subtitles that are being translated: 1 1 00:00:01,481 --> 00:00:03,730 (Instructor) Welcome to the final coding challenge 2 2 00:00:03,730 --> 00:00:05,430 of this section. 3 3 00:00:05,430 --> 00:00:07,710 And this one can really be seen 4 4 00:00:07,710 --> 00:00:10,750 as a final test of this section. 5 5 00:00:10,750 --> 00:00:12,140 So we're going to practice most 6 6 00:00:12,140 --> 00:00:16,373 of what we've been doing here and so let's get started. 7 7 00:00:18,250 --> 00:00:19,480 And in this challenge, 8 8 00:00:19,480 --> 00:00:22,870 we are back to Julia and Kate studying dogs. 9 9 00:00:22,870 --> 00:00:24,569 And this time they are studying 10 10 00:00:24,569 --> 00:00:27,963 whether dogs are eating too much or too little. 11 11 00:00:28,918 --> 00:00:33,650 So eating too much means that the dogs current food portion 12 12 00:00:33,650 --> 00:00:36,420 is larger than the recommended portion. 13 13 00:00:36,420 --> 00:00:39,570 And eating too little is the opposite. 14 14 00:00:39,570 --> 00:00:42,410 And then there's also eating an okay amount. 15 15 00:00:42,410 --> 00:00:45,930 And so that's when the dog's current food portion 16 16 00:00:45,930 --> 00:00:48,340 is within the range 10% above, 17 17 00:00:48,340 --> 00:00:51,370 and 10% below the recommended portion. 18 18 00:00:51,370 --> 00:00:54,463 And we will check that out in detail in a second. 19 19 00:00:55,719 --> 00:00:58,490 And so here are your tasks. 20 20 00:00:58,490 --> 00:01:00,890 And actually, each of them can be seen 21 21 00:01:00,890 --> 00:01:02,450 as a separate challenge. 22 22 00:01:02,450 --> 00:01:04,440 So there are eight of them. 23 23 00:01:04,440 --> 00:01:06,910 So this is going to be a long one. 24 24 00:01:06,910 --> 00:01:09,930 And some of them are actually a little bit tricky. 25 25 00:01:09,930 --> 00:01:14,860 So a bit hard to solve and that is one more time on purpose. 26 26 00:01:14,860 --> 00:01:17,580 So that you can actually challenge yourself, 27 27 00:01:17,580 --> 00:01:19,270 and try to do a little bit more 28 28 00:01:19,270 --> 00:01:22,300 than just what we learned here in these videos. 29 29 00:01:22,300 --> 00:01:25,510 And as always, if you cannot solve one of them on your own, 30 30 00:01:25,510 --> 00:01:27,960 then just go ahead and watch the solution, 31 31 00:01:27,960 --> 00:01:30,123 and then go back to the next point. 32 32 00:01:31,088 --> 00:01:34,930 Now anyway, let's get started here. 33 33 00:01:34,930 --> 00:01:37,690 And the first task is to loop over the array 34 34 00:01:37,690 --> 00:01:40,273 that contains the dog objects. 35 35 00:01:41,410 --> 00:01:43,540 So that is this object here. 36 36 00:01:43,540 --> 00:01:46,200 And this is the data that we're going to work with. 37 37 00:01:46,200 --> 00:01:48,390 So it's this array called dogs. 38 38 00:01:48,390 --> 00:01:50,400 And in each position of the array, 39 39 00:01:50,400 --> 00:01:52,823 we have one object per dog. 40 40 00:01:56,070 --> 00:01:59,550 So your task is to loop over that array. 41 41 00:01:59,550 --> 00:02:01,700 And then for each dog to calculate 42 42 00:02:01,700 --> 00:02:03,800 the recommended food portion, 43 43 00:02:03,800 --> 00:02:07,590 and then to add it to the object as a new property. 44 44 00:02:07,590 --> 00:02:09,800 So do not create a new array here, 45 45 00:02:09,800 --> 00:02:12,800 just loop over the array that we already have, 46 46 00:02:12,800 --> 00:02:16,960 and add the recommended food portion as a property. 47 47 00:02:16,960 --> 00:02:19,950 And so I hope you know which array method 48 48 00:02:19,950 --> 00:02:21,730 you need to use for that. 49 49 00:02:21,730 --> 00:02:24,920 And to calculate that recommended food portion, 50 50 00:02:24,920 --> 00:02:27,220 simply take the weight of the dog 51 51 00:02:27,220 --> 00:02:31,673 and elevate it to 0.75 times 28. 52 52 00:02:33,650 --> 00:02:37,850 Then next up, find Sarah's dog and log to the console, 53 53 00:02:37,850 --> 00:02:41,050 whether it is eating too much or too little. 54 54 00:02:41,050 --> 00:02:43,379 Now in this one, it's important to keep in mind, 55 55 00:02:43,379 --> 00:02:47,070 or important to notice that these owners 56 56 00:02:47,070 --> 00:02:50,490 are actually inside an array. 57 57 00:02:50,490 --> 00:02:55,490 And so this makes this task a little bit more tricky. 58 58 00:02:55,570 --> 00:02:58,003 And so again, that is on purpose. 59 59 00:02:59,280 --> 00:03:01,440 Next up, create an array containing 60 60 00:03:01,440 --> 00:03:05,160 all the owners of dogs who eat too much. 61 61 00:03:05,160 --> 00:03:08,350 So call this one owners eat too much 62 62 00:03:08,350 --> 00:03:10,590 and then an array with the opposite. 63 63 00:03:10,590 --> 00:03:14,110 So with owners of dogs who eat too little. 64 64 00:03:14,110 --> 00:03:16,360 Then log a string to the console 65 65 00:03:16,360 --> 00:03:21,360 for each of the arrays that we created previously like this. 66 66 00:03:21,730 --> 00:03:25,890 So Matilda, Alice and Bob's dogs eat too much. 67 67 00:03:25,890 --> 00:03:27,950 So that's based on this array. 68 68 00:03:27,950 --> 00:03:31,933 And then based on this array, a string like this. 69 69 00:03:33,241 --> 00:03:37,190 Then afterwards, log to the console, 70 70 00:03:37,190 --> 00:03:41,739 whether there is any dog eating an okay amount of food. 71 71 00:03:41,739 --> 00:03:43,760 And so let's take a look 72 72 00:03:43,760 --> 00:03:47,023 at what an okay amount of food actually means. 73 73 00:03:48,680 --> 00:03:50,490 So here we have to send two 74 74 00:03:50,490 --> 00:03:53,830 and so being within the range 10% above 75 75 00:03:53,830 --> 00:03:57,790 and 10% below means that the current food portion, 76 76 00:03:57,790 --> 00:04:00,450 which is stored here in this property 77 77 00:04:00,450 --> 00:04:03,320 should be greater than the recommended food portion 78 78 00:04:03,320 --> 00:04:07,090 that you calculated before times 0.9. 79 79 00:04:07,090 --> 00:04:10,220 So that's 90% and at the same time, 80 80 00:04:10,220 --> 00:04:14,041 it should be less than 110% basically, 81 81 00:04:14,041 --> 00:04:16,460 of the recommended amount. 82 82 00:04:16,460 --> 00:04:19,390 So these two conditions here at the same time 83 83 00:04:19,390 --> 00:04:22,523 mean that the dog is eating an okay amount of food. 84 84 00:04:23,380 --> 00:04:26,110 So basically, it's what we see here. 85 85 00:04:26,110 --> 00:04:28,640 So the current portion should be between 90 86 86 00:04:28,640 --> 00:04:31,803 and 110% of the recommended. 87 87 00:04:33,480 --> 00:04:36,240 Then number seven, create an array containing 88 88 00:04:36,240 --> 00:04:40,320 all the dogs that are eating an okay amount of food 89 89 00:04:40,320 --> 00:04:42,910 and I want you to reuse the condition 90 90 00:04:42,910 --> 00:04:45,463 that we created before here are a number of six. 91 91 00:04:46,680 --> 00:04:50,570 Finally, create a shallow copy of the dog's array 92 92 00:04:50,570 --> 00:04:53,780 and then sort it by the recommended food portion 93 93 00:04:53,780 --> 00:04:55,690 in an ascending order. 94 94 00:04:55,690 --> 00:04:56,860 Now just keep in mind 95 95 00:04:56,860 --> 00:05:00,393 that the portions are inside the arrays objects. 96 96 00:05:01,430 --> 00:05:03,683 Okay, so to sort this array, 97 97 00:05:03,683 --> 00:05:07,150 it's a little bit trickier than what we did before. 98 98 00:05:07,150 --> 00:05:12,120 Because yeah, the value is now here inside of an object, 99 99 00:05:12,120 --> 00:05:14,540 and not just in the array itself. 100 100 00:05:14,540 --> 00:05:15,690 But the way that we write 101 101 00:05:15,690 --> 00:05:18,100 the callback function is pretty similar. 102 102 00:05:18,100 --> 00:05:21,000 So we will still have the ANP parameters, 103 103 00:05:21,000 --> 00:05:22,730 but these are no objects. 104 104 00:05:22,730 --> 00:05:25,510 And so to compare the recommended food portion, 105 105 00:05:25,510 --> 00:05:27,042 you will have to get that property 106 106 00:05:27,042 --> 00:05:29,113 out of each of these objects. 107 107 00:05:30,040 --> 00:05:32,766 So yeah, that's it. 108 108 00:05:32,766 --> 00:05:35,390 It's probably going to take you some time. 109 109 00:05:35,390 --> 00:05:36,890 But what matters most 110 110 00:05:36,890 --> 00:05:40,830 is that you practice and that you don't give up. 111 111 00:05:40,830 --> 00:05:43,700 But anyway, let's take now like half an hour, 112 112 00:05:43,700 --> 00:05:46,377 or even one hour to solve this one 113 113 00:05:46,377 --> 00:05:48,083 and then I see you back here. 114 114 00:05:51,722 --> 00:05:56,170 So let's get started with the solution. 115 115 00:05:56,170 --> 00:05:58,060 So the first one is to calculate 116 116 00:05:58,060 --> 00:06:00,963 the recommended food for each of the dog. 117 117 00:06:01,940 --> 00:06:05,300 Now, as I said, you should not create a new array, 118 118 00:06:05,300 --> 00:06:08,890 but simply loop over the already existing array. 119 119 00:06:08,890 --> 00:06:12,960 So this dogs array, actually copy it here. 120 120 00:06:12,960 --> 00:06:13,873 So copy. 121 121 00:06:17,500 --> 00:06:21,420 So looping over this array and then to each object, 122 122 00:06:21,420 --> 00:06:24,100 we want to add a new property. 123 123 00:06:24,100 --> 00:06:27,083 And so the for each method is the way to go here. 124 124 00:06:29,120 --> 00:06:31,653 Then each element is a dog. 125 125 00:06:32,500 --> 00:06:36,630 And what we want to do is to add a property. 126 126 00:06:36,630 --> 00:06:41,290 So dog.recommended food is equal 127 127 00:06:42,147 --> 00:06:47,147 to dog.weight elevated 0.75 times 28. 128 128 00:06:53,240 --> 00:06:55,303 And now let's take a look at the dogs. 129 129 00:07:00,280 --> 00:07:02,630 And indeed, now they have the recommended food. 130 130 00:07:03,600 --> 00:07:07,320 Now let's just get rid of this decimal part here. 131 131 00:07:07,320 --> 00:07:12,320 So let's say here, math.trunc. 132 132 00:07:14,080 --> 00:07:17,513 So we use this one before we simply truncate. 133 133 00:07:18,530 --> 00:07:21,210 So we cut the decimal parts. 134 134 00:07:21,210 --> 00:07:25,493 And so that's number one and now number two, 135 135 00:07:26,940 --> 00:07:28,323 let's check it out again. 136 136 00:07:29,750 --> 00:07:33,640 So we need to find Sarah's dog and then log to the console, 137 137 00:07:33,640 --> 00:07:37,070 whether it's eating too much or too little. 138 138 00:07:37,070 --> 00:07:40,653 So basically, we need to find the object here. 139 139 00:07:42,630 --> 00:07:45,120 So in this case, that's going to be this one. 140 140 00:07:45,120 --> 00:07:47,040 So we need to find this object, 141 141 00:07:47,040 --> 00:07:49,290 and then compare the recommended food 142 142 00:07:49,290 --> 00:07:52,363 we just calculated with the current food. 143 143 00:07:53,620 --> 00:07:58,143 So the trickiest part here is going to be to find the owner. 144 144 00:07:59,270 --> 00:08:01,660 But I believe we can do it. 145 145 00:08:01,660 --> 00:08:06,660 So let's call this one dogSarah, then it's dogs. 146 146 00:08:08,310 --> 00:08:10,050 And we use the find method, 147 147 00:08:10,050 --> 00:08:12,180 because we want to find one element 148 148 00:08:12,180 --> 00:08:15,350 of the array based on a condition. 149 149 00:08:15,350 --> 00:08:18,750 So in each iteration, we have one dog. 150 150 00:08:18,750 --> 00:08:23,340 And now we want to take dog.owners. 151 151 00:08:23,340 --> 00:08:27,130 And now this itself is also an array. 152 152 00:08:27,130 --> 00:08:28,483 So it is this here. 153 153 00:08:29,670 --> 00:08:34,540 And what we want now is for this array to include Sarah. 154 154 00:08:34,540 --> 00:08:39,540 And so we can do this, includes Sarah and that's it. 155 155 00:08:41,880 --> 00:08:45,270 This is how we get our true or false value. 156 156 00:08:45,270 --> 00:08:48,980 So remember that in the callback of the find method, 157 157 00:08:48,980 --> 00:08:52,090 we need to return a true or a false value. 158 158 00:08:52,090 --> 00:08:53,930 And then the find method will return 159 159 00:08:53,930 --> 00:08:57,460 the first element for which the condition is true. 160 160 00:08:57,460 --> 00:09:00,930 And in this case, we get the true or false value 161 161 00:09:00,930 --> 00:09:05,360 by calling the includes method on the owners array. 162 162 00:09:05,360 --> 00:09:09,180 And so when the array of owners includes Sarah, 163 163 00:09:09,180 --> 00:09:10,880 then that condition is true. 164 164 00:09:10,880 --> 00:09:13,313 And then we are going to get this object. 165 165 00:09:14,660 --> 00:09:18,080 So let's just make sure here and let's see. 166 166 00:09:22,590 --> 00:09:25,423 And indeed, it is the correct object. 167 167 00:09:26,610 --> 00:09:28,113 We need some more space here. 168 168 00:09:29,410 --> 00:09:31,320 This we don't need any more. 169 169 00:09:31,320 --> 00:09:33,270 And now we just need to log to the console 170 170 00:09:33,270 --> 00:09:36,690 whether the dog is eating too much or not. 171 171 00:09:36,690 --> 00:09:39,310 And we already know that it's eating too much 172 172 00:09:39,310 --> 00:09:43,827 because the current food is 275 and the recommended is 191. 173 173 00:09:46,430 --> 00:09:51,430 So let's log Sarah's dog is eating. 174 174 00:09:54,960 --> 00:09:57,090 And here I'm going to use my old friend, 175 175 00:09:57,090 --> 00:10:01,967 the ternary operator, Sarah.current food. 176 176 00:10:03,350 --> 00:10:08,253 If it's greater, then dogSarah.recommended food. 177 177 00:10:09,900 --> 00:10:14,670 Well then here we want to have much, 178 178 00:10:14,670 --> 00:10:15,703 because in this situation, 179 179 00:10:15,703 --> 00:10:18,440 the dog is clearly eating too much. 180 180 00:10:18,440 --> 00:10:22,423 Now of course this needs to be here inside the curly braces. 181 181 00:10:25,440 --> 00:10:28,830 And here now it's correct. 182 182 00:10:28,830 --> 00:10:31,200 So we're asking basically this question. 183 183 00:10:31,200 --> 00:10:34,000 So if the current food is more than the recommended, 184 184 00:10:34,000 --> 00:10:39,000 then the dog is eating too much and else too little. 185 185 00:10:41,720 --> 00:10:45,690 And so indeed, Sarah's dog is eating too much. 186 186 00:10:45,690 --> 00:10:48,000 So that's the conclusion we had already reached 187 187 00:10:48,000 --> 00:10:49,880 by looking here at the numbers. 188 188 00:10:49,880 --> 00:10:51,253 Okay, moving on. 189 189 00:10:52,970 --> 00:10:57,970 Let's take a second here to look at the exercise again. 190 190 00:10:58,620 --> 00:11:00,270 So create an array containing 191 191 00:11:00,270 --> 00:11:03,930 all owners of dogs who eat too much. 192 192 00:11:03,930 --> 00:11:05,830 So let's copy this name. 193 193 00:11:05,830 --> 00:11:08,923 And then also one where they eat too little. 194 194 00:11:13,767 --> 00:11:15,363 So how are we going to do that? 195 195 00:11:17,150 --> 00:11:19,620 Well, we know that we want a new array 196 196 00:11:19,620 --> 00:11:23,136 based on the existing dog's array. 197 197 00:11:23,136 --> 00:11:28,136 And we want to create this new array based on a condition. 198 198 00:11:28,170 --> 00:11:31,210 So once again, we want to compare the current food 199 199 00:11:31,210 --> 00:11:33,426 to the recommended food. 200 200 00:11:33,426 --> 00:11:38,053 And therefore the correct method to use here is the filter. 201 201 00:11:40,246 --> 00:11:43,850 So in each iteration, we get a dog. 202 202 00:11:43,850 --> 00:11:48,405 And we're going to return whether this dog's current food 203 203 00:11:48,405 --> 00:11:53,405 is greater than the dog recommended food. 204 204 00:11:55,030 --> 00:11:59,490 Because here we are looking for the dogs that eat too much. 205 205 00:11:59,490 --> 00:12:03,230 And so that means that the current food 206 206 00:12:03,230 --> 00:12:04,893 is greater than the recommended. 207 207 00:12:06,353 --> 00:12:09,810 So this will give us the dogs. 208 208 00:12:09,810 --> 00:12:14,700 But let's start by taking a look at this variable for now, 209 209 00:12:14,700 --> 00:12:16,250 even though we want the owners. 210 210 00:12:20,900 --> 00:12:24,936 So this one doesn't show it to us. 211 211 00:12:24,936 --> 00:12:28,510 But yes, so this dog here 212 212 00:12:28,510 --> 00:12:30,333 is eating more than the recommended. 213 213 00:12:31,385 --> 00:12:36,385 Now, we now want to get the owner or actually the owners. 214 214 00:12:38,700 --> 00:12:41,210 So again, we want to create a new array 215 215 00:12:41,210 --> 00:12:43,400 based on an existing array. 216 216 00:12:43,400 --> 00:12:45,200 And this time, this new array should 217 217 00:12:45,200 --> 00:12:47,490 have the same length as before. 218 218 00:12:47,490 --> 00:12:50,710 We simply want to take something out of the original array 219 219 00:12:50,710 --> 00:12:53,090 and put it into the new array. 220 220 00:12:53,090 --> 00:12:56,133 And so that means we're going to use map. 221 221 00:12:57,110 --> 00:12:59,450 So once again, we have a dog 222 222 00:12:59,450 --> 00:13:04,312 and we want to return the dog.owners. 223 223 00:13:04,312 --> 00:13:07,560 And now we have an array of arrays, 224 224 00:13:07,560 --> 00:13:11,580 where one is Matilda, and the other one is Sarah and John. 225 225 00:13:11,580 --> 00:13:13,700 And so finally, the next step, 226 226 00:13:13,700 --> 00:13:17,060 to transform all of this into just one array, 227 227 00:13:17,060 --> 00:13:18,823 is to call flat. 228 228 00:13:20,554 --> 00:13:25,210 And so indeed, we end up with this array 229 229 00:13:25,210 --> 00:13:26,620 with just one level. 230 230 00:13:26,620 --> 00:13:30,420 And with all the owners of all the dogs that eat too much. 231 231 00:13:30,420 --> 00:13:33,460 So great and maybe you can see here 232 232 00:13:33,460 --> 00:13:35,880 that we can actually do even better, 233 233 00:13:35,880 --> 00:13:39,550 because whenever we have a map combined with a flat, 234 234 00:13:39,550 --> 00:13:42,650 we can instead use flat map. 235 235 00:13:42,650 --> 00:13:47,650 So let's transform this year into flat map. 236 236 00:13:48,380 --> 00:13:50,552 And then we don't even need this part 237 237 00:13:50,552 --> 00:13:53,303 and the result is the same indeed. 238 238 00:13:55,536 --> 00:14:00,220 And based on this one, we can easily create the owners 239 239 00:14:01,390 --> 00:14:03,573 where the dogs eat too little. 240 240 00:14:05,920 --> 00:14:09,423 So all we need to do is to invert this sign. 241 241 00:14:10,880 --> 00:14:12,860 Let's get rid of this one here. 242 242 00:14:12,860 --> 00:14:15,713 And so these are the other three owners basically. 243 243 00:14:17,827 --> 00:14:22,827 Next up, our task is to create some strings. 244 244 00:14:22,930 --> 00:14:24,663 So let me just copy the strings. 245 245 00:14:28,070 --> 00:14:31,703 And so that's based on the arrays that we just created. 246 246 00:14:41,620 --> 00:14:43,163 So these are the two strings. 247 247 00:14:44,090 --> 00:14:46,100 And actually they will not be the same. 248 248 00:14:46,100 --> 00:14:47,950 So this is just an example. 249 249 00:14:47,950 --> 00:14:52,140 So here we see Alice, Bob and Michael's dogs are together, 250 250 00:14:52,140 --> 00:14:53,990 and here they are not. 251 251 00:14:53,990 --> 00:14:56,840 So the string will be different, but that doesn't matter. 252 252 00:14:59,480 --> 00:15:04,480 So what matters is that here we have dogs eat too much. 253 253 00:15:05,650 --> 00:15:09,940 And so now all we do, is to take the owners 254 254 00:15:09,940 --> 00:15:11,943 that we already have eat too much. 255 255 00:15:13,170 --> 00:15:15,410 And essentially join them together 256 256 00:15:15,410 --> 00:15:19,393 using the separator string of and, like this. 257 257 00:15:21,240 --> 00:15:23,140 And so now we get this array 258 258 00:15:23,140 --> 00:15:27,180 here Matilda, Sarah and John dog. 259 259 00:15:27,180 --> 00:15:32,180 So let's just add this eat too much. 260 260 00:15:34,530 --> 00:15:38,652 And now the other way around eat too little 261 261 00:15:38,652 --> 00:15:42,483 and here too little as well. 262 262 00:15:43,900 --> 00:15:44,743 Beautiful. 263 263 00:15:47,810 --> 00:15:50,120 So we're making good progress here, 264 264 00:15:50,120 --> 00:15:51,803 let's move on to number five. 265 265 00:15:52,660 --> 00:15:54,943 So log whether there is any dog eating exactly 266 266 00:15:54,943 --> 00:15:58,970 the amount of food that is recommended. 267 267 00:15:58,970 --> 00:16:01,240 So whenever you see the word any, 268 268 00:16:01,240 --> 00:16:04,093 you can think of the sum method. 269 269 00:16:05,340 --> 00:16:06,963 So remember that the sum method 270 270 00:16:06,963 --> 00:16:10,520 will return true if at least one of the elements 271 271 00:16:10,520 --> 00:16:13,323 in the array satisfies a certain condition. 272 272 00:16:14,580 --> 00:16:19,053 So log to the console, dogs.sum. 273 273 00:16:23,040 --> 00:16:24,830 And so one more time, 274 274 00:16:24,830 --> 00:16:29,830 we are comparing the current food with the recommended food. 275 275 00:16:30,360 --> 00:16:34,320 And this time, we want to know if there is at least one dog 276 276 00:16:34,320 --> 00:16:38,560 eating exactly the same amount as the recommended portion. 277 277 00:16:38,560 --> 00:16:41,320 And so we use the equal operator here. 278 278 00:16:41,320 --> 00:16:44,993 So current and recommended food. 279 279 00:16:46,700 --> 00:16:48,533 And well, there is none. 280 280 00:16:49,580 --> 00:16:52,793 Let's take a look at our dogs here just to confirm that. 281 281 00:16:57,430 --> 00:17:00,053 So these are different, these are different, 282 282 00:17:01,150 --> 00:17:05,090 these are different and also probably yeah, 283 283 00:17:05,090 --> 00:17:07,120 this is also different. 284 284 00:17:07,120 --> 00:17:10,240 And therefore, if all of them are false, 285 285 00:17:10,240 --> 00:17:13,473 then the sum method also returns false. 286 286 00:17:17,360 --> 00:17:20,100 Number six, log to the console, 287 287 00:17:20,100 --> 00:17:23,533 whether there is any dog eating an okay amount of food. 288 288 00:17:24,957 --> 00:17:28,780 And so now this formula here comes into play. 289 289 00:17:28,780 --> 00:17:32,003 Let's copy it just so we see it down here. 290 290 00:17:35,930 --> 00:17:37,567 And so once again, 291 291 00:17:37,567 --> 00:17:41,790 the goal is to simply return true or false, 292 292 00:17:41,790 --> 00:17:44,150 whether there is at least one dog 293 293 00:17:44,150 --> 00:17:46,580 eating an okay amount of food. 294 294 00:17:46,580 --> 00:17:48,313 So we need the sum method again. 295 295 00:17:49,490 --> 00:17:53,430 And now this a little bit more complex condition. 296 296 00:17:53,430 --> 00:17:57,410 So dog.current food portion 297 297 00:17:57,410 --> 00:18:02,317 needs to be greater than the recommended times 0.9. 298 298 00:18:07,240 --> 00:18:11,203 So that's 90% and then at the same time, 299 299 00:18:12,730 --> 00:18:16,313 so this, (laughs) now let me just copy it here. 300 300 00:18:19,010 --> 00:18:20,900 So at the same time, 301 301 00:18:20,900 --> 00:18:24,563 the dog should also be eating less than 110% 302 302 00:18:27,977 --> 00:18:29,323 of the recommended amount. 303 303 00:18:30,980 --> 00:18:33,230 And so now we get true. 304 304 00:18:33,230 --> 00:18:37,730 So there is at least one dog but we don't know how many. 305 305 00:18:37,730 --> 00:18:41,380 And so that's the task basically of the next point, 306 306 00:18:41,380 --> 00:18:43,610 which is to filter out all the dogs 307 307 00:18:43,610 --> 00:18:47,570 that are actually eating this okay amount of food. 308 308 00:18:47,570 --> 00:18:49,490 And for that we should also export 309 309 00:18:49,490 --> 00:18:52,063 this condition into a separate function. 310 310 00:18:52,950 --> 00:18:55,565 So this is really just a function. 311 311 00:18:55,565 --> 00:19:00,163 So we can take it and store it into its own variable. 312 312 00:19:01,120 --> 00:19:05,390 And let's call it check eating okay. 313 313 00:19:08,938 --> 00:19:10,570 And then simply the function. 314 314 00:19:10,570 --> 00:19:12,763 And so here, we can then use that function. 315 315 00:19:15,030 --> 00:19:18,280 And yeah, we still get the same result. 316 316 00:19:18,280 --> 00:19:21,840 And now as I was just saying, 317 317 00:19:21,840 --> 00:19:24,240 the goal here is to create an array 318 318 00:19:24,240 --> 00:19:27,020 containing only the dogs that are eating 319 319 00:19:27,020 --> 00:19:28,843 an okay amount of food. 320 320 00:19:30,240 --> 00:19:34,740 So we want a new array based on an existing array, 321 321 00:19:34,740 --> 00:19:37,000 but only with some of the elements. 322 322 00:19:37,000 --> 00:19:41,163 And so it is time again for using the filter method. 323 323 00:19:42,810 --> 00:19:47,690 So docs dot filter and now this is very easy, 324 324 00:19:47,690 --> 00:19:50,707 because we already have this condition 325 325 00:19:50,707 --> 00:19:53,323 callback function here in this variable. 326 326 00:19:55,740 --> 00:20:00,040 And well, we only have one dog in this condition as you see. 327 327 00:20:00,040 --> 00:20:01,667 So that's Michael's dog, 328 328 00:20:01,667 --> 00:20:05,460 where the recommended food is indeed pretty close 329 329 00:20:05,460 --> 00:20:07,318 to the current food. 330 330 00:20:07,318 --> 00:20:10,310 And so we consider that this is an okay amount of food 331 331 00:20:10,310 --> 00:20:12,203 to eat for the dog. 332 332 00:20:13,190 --> 00:20:15,200 Okay, almost ready here. 333 333 00:20:15,200 --> 00:20:17,375 So I told you this is a long one. 334 334 00:20:17,375 --> 00:20:20,320 But I hope you're having fun with this one. 335 335 00:20:20,320 --> 00:20:23,040 This kind of seems like a real world challenge. 336 336 00:20:23,040 --> 00:20:26,130 So like a real world task, doesn't it? 337 337 00:20:26,130 --> 00:20:28,950 So it took quite some time and designing this challenge. 338 338 00:20:28,950 --> 00:20:32,000 And even that was also a lot of fun. 339 339 00:20:32,000 --> 00:20:36,660 But anyway, let's now create a copy of the dogs array, 340 340 00:20:36,660 --> 00:20:39,823 and then sorted by the recommended food portion. 341 341 00:20:41,660 --> 00:20:44,060 So let me actually copy this 342 342 00:20:44,060 --> 00:20:47,573 so we don't forget what we have to do here. 343 343 00:20:51,070 --> 00:20:53,523 So we start by creating a copy. 344 344 00:20:55,020 --> 00:21:00,020 So dogs.copy, no dot of course, 345 345 00:21:00,810 --> 00:21:02,950 just the name is dogs copy. 346 346 00:21:02,950 --> 00:21:07,950 And so let's use dogs.slice for that. 347 347 00:21:08,270 --> 00:21:10,930 And actually, we can call the sort method 348 348 00:21:10,930 --> 00:21:12,433 then immediately on that. 349 349 00:21:13,546 --> 00:21:17,660 So here, we are going to need a callback function as always, 350 350 00:21:17,660 --> 00:21:19,470 which is the sorting function. 351 351 00:21:19,470 --> 00:21:24,033 And this always has a and b as the parameters. 352 352 00:21:25,050 --> 00:21:28,410 So we could call them something else of course here, 353 353 00:21:28,410 --> 00:21:31,390 but I like to always call them a and b. 354 354 00:21:31,390 --> 00:21:33,966 And actually, we don't even need this block here. 355 355 00:21:33,966 --> 00:21:35,860 So remember that before, 356 356 00:21:35,860 --> 00:21:39,450 when we wanted to sort an array in an ascending order, 357 357 00:21:39,450 --> 00:21:43,800 we simply would do a minus b like this. 358 358 00:21:43,800 --> 00:21:47,893 But this was when we had an array, simply like this. 359 359 00:21:49,390 --> 00:21:50,710 So just with numbers, 360 360 00:21:50,710 --> 00:21:53,750 but now we have these numbers here in objects. 361 361 00:21:53,750 --> 00:21:56,503 And so a and b, are now the objects. 362 362 00:21:57,360 --> 00:22:00,450 However, the values that we want to subtract 363 363 00:22:00,450 --> 00:22:02,840 are in these objects and we can simply 364 364 00:22:02,840 --> 00:22:03,940 get them out of there. 365 365 00:22:05,500 --> 00:22:08,570 So we want to sort by the recommended food portion. 366 366 00:22:08,570 --> 00:22:10,923 And so let's simply do this. 367 367 00:22:16,590 --> 00:22:18,263 And that's actually it. 368 368 00:22:19,507 --> 00:22:21,643 Let's call this your dog's sorted. 369 369 00:22:24,615 --> 00:22:28,760 And then let's log that to the console here. 370 370 00:22:29,750 --> 00:22:31,203 Dog's sorted. 371 371 00:22:32,810 --> 00:22:35,543 Let's see and yeah, that worked. 372 372 00:22:36,690 --> 00:22:38,523 Oh, actually we cannot see it yet. 373 373 00:22:41,640 --> 00:22:45,060 So yeah, here is the recommended food. 374 374 00:22:45,060 --> 00:22:49,400 So we start with the lowest one, then 191. 375 375 00:22:49,400 --> 00:22:52,440 And you see that indeed, it is in an ascending order. 376 376 00:22:52,440 --> 00:22:55,017 So 284 and 376. 377 377 00:22:59,150 --> 00:23:00,680 So that worked. 378 378 00:23:00,680 --> 00:23:03,802 And so we finished this coding challenge. 379 379 00:23:03,802 --> 00:23:06,110 This was a lot of work. 380 380 00:23:06,110 --> 00:23:09,270 And as I just said, also a lot of fun. 381 381 00:23:09,270 --> 00:23:10,788 And I hope you felt the same. 382 382 00:23:10,788 --> 00:23:15,480 And also that you felt the same for this entire section. 383 383 00:23:15,480 --> 00:23:18,270 So this project was a great project in my opinion, 384 384 00:23:18,270 --> 00:23:21,376 it was a lot of fun to build it together with you, 385 385 00:23:21,376 --> 00:23:25,600 and to put it together and design it in the first place. 386 386 00:23:25,600 --> 00:23:28,440 So I hope you're proud of what you achieved here. 387 387 00:23:28,440 --> 00:23:31,290 And one more time I want to congratulate you 388 388 00:23:31,290 --> 00:23:34,250 for making it this far and still sticking 389 389 00:23:34,250 --> 00:23:37,190 with this quite long course. 390 390 00:23:37,190 --> 00:23:39,830 Anyway with that, I see you in the next section, 391 391 00:23:39,830 --> 00:23:41,960 where we will actually continue building 392 392 00:23:41,960 --> 00:23:45,463 on this project by adding a couple of new things to it. 34301