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These are the user uploaded subtitles that are being translated: 1 1 00:00:01,390 --> 00:00:05,320 All right, here goes coding challenge number two, 2 2 00:00:05,320 --> 00:00:07,693 which is gonna be all about arrays. 3 3 00:00:09,420 --> 00:00:10,320 And in this one, 4 4 00:00:10,320 --> 00:00:12,910 we're gonna go back to the tip calculator 5 5 00:00:12,910 --> 00:00:15,540 that we built in the previous section. 6 6 00:00:15,540 --> 00:00:18,140 And we're still using the same rules as before. 7 7 00:00:18,140 --> 00:00:23,140 So we tip 15% of the bill value, if it's between 50 and 300. 8 8 00:00:24,070 --> 00:00:28,050 And if the value is different, so outside of this range, 9 9 00:00:28,050 --> 00:00:30,691 the tip is 20%. 10 10 00:00:30,691 --> 00:00:32,780 And so here are your tasks. 11 11 00:00:32,780 --> 00:00:35,580 First, write a function called calcTip, 12 12 00:00:35,580 --> 00:00:38,850 which takes any bill value as an input, 13 13 00:00:38,850 --> 00:00:40,970 and returns the corresponding tip. 14 14 00:00:40,970 --> 00:00:43,320 And so that's gonna be based on the rules 15 15 00:00:43,320 --> 00:00:45,060 that I just mentioned. 16 16 00:00:45,060 --> 00:00:47,520 And to do this, you can actually check out the code 17 17 00:00:47,520 --> 00:00:49,860 from the first tip calculator challenge 18 18 00:00:49,860 --> 00:00:51,670 that we did in the last section. 19 19 00:00:51,670 --> 00:00:53,350 So you can copy the code there. 20 20 00:00:53,350 --> 00:00:56,540 Or if you want, you can also code this from scratch, 21 21 00:00:56,540 --> 00:00:58,870 just to remember how to do it. 22 22 00:00:58,870 --> 00:01:03,170 And now in number two, we're finally gonna use arrays. 23 23 00:01:03,170 --> 00:01:06,260 So here, we're gonna create an array called bills, 24 24 00:01:06,260 --> 00:01:11,260 which will contain the test data that we have down here. 25 25 00:01:11,300 --> 00:01:13,710 So these are the three bill values 26 26 00:01:13,710 --> 00:01:16,210 for which we want to calculate the tips. 27 27 00:01:16,210 --> 00:01:19,810 And so that's what we do in point number three. 28 28 00:01:19,810 --> 00:01:22,450 So here, we create an array called tips, 29 29 00:01:22,450 --> 00:01:24,500 which will contain the tip value 30 30 00:01:24,500 --> 00:01:26,757 for each of the three bills. 31 31 00:01:26,757 --> 00:01:30,119 And this is where we're gonna use the calcTip function 32 32 00:01:30,119 --> 00:01:32,040 that we created before. 33 33 00:01:32,040 --> 00:01:33,790 So that's the basic challenge. 34 34 00:01:33,790 --> 00:01:36,210 And if you wanna take it one step further, 35 35 00:01:36,210 --> 00:01:39,220 you can even take the bonus question. 36 36 00:01:39,220 --> 00:01:40,730 So number four here, 37 37 00:01:40,730 --> 00:01:44,580 in which I ask you to create an array called total, 38 38 00:01:44,580 --> 00:01:47,390 which will have the total values. 39 39 00:01:47,390 --> 00:01:50,520 So that's the bill plus the tip. 40 40 00:01:50,520 --> 00:01:53,100 So I hope this one isn't too hard. 41 41 00:01:53,100 --> 00:01:56,250 Basically, it's similar to one of the examples actually, 42 42 00:01:56,250 --> 00:01:59,900 that we did in one of the lectures about the arrays. 43 43 00:01:59,900 --> 00:02:00,750 And once again, 44 44 00:02:00,750 --> 00:02:04,080 I also have a hint to help you solving this one. 45 45 00:02:04,080 --> 00:02:07,250 But if you want to try it on your own without the hint 46 46 00:02:07,250 --> 00:02:09,873 then pause video now, and good luck. 47 47 00:02:11,220 --> 00:02:13,210 But if you want to hint, 48 48 00:02:13,210 --> 00:02:15,730 well, then here it goes. 49 49 00:02:15,730 --> 00:02:20,220 So remember that an array needs a value in each position. 50 50 00:02:20,220 --> 00:02:21,053 But that value 51 51 00:02:21,053 --> 00:02:24,710 can actually be the returned value of a function. 52 52 00:02:24,710 --> 00:02:26,070 So as an array value, 53 53 00:02:26,070 --> 00:02:29,860 you can basically just call a function. Alright. 54 54 00:02:29,860 --> 00:02:31,680 And again, that is similar 55 55 00:02:31,680 --> 00:02:35,860 to something that we did in one of the array lectures. 56 56 00:02:35,860 --> 00:02:37,360 So pause the video now, 57 57 00:02:37,360 --> 00:02:40,003 and I see you with my solution in a second. 58 58 00:02:42,840 --> 00:02:47,003 Okay, and I'm gonna start by creating the calcTip function. 59 59 00:02:52,860 --> 00:02:57,050 And I'm gonna start doing it with a function expression. 60 60 00:02:57,050 --> 00:03:00,293 So this one will receive a bill as an input, 61 61 00:03:01,510 --> 00:03:02,803 I believe, I think, 62 62 00:03:03,890 --> 00:03:07,490 yeah, so calcTip takes any bill as an input. 63 63 00:03:07,490 --> 00:03:09,360 So let's simply call it bill. 64 64 00:03:09,360 --> 00:03:13,120 And then what we want to return is the tip. 65 65 00:03:13,120 --> 00:03:15,310 And here I'm gonna write the exact same code 66 66 00:03:15,310 --> 00:03:17,280 as we did in the other challenge. 67 67 00:03:17,280 --> 00:03:19,723 So there's no need to explain it all again, 68 68 00:03:20,590 --> 00:03:22,720 it would just be a waste of time. 69 69 00:03:22,720 --> 00:03:27,720 So if the bill value is between 50 and 300, 70 70 00:03:29,520 --> 00:03:33,800 so less or equal than 300. 71 71 00:03:33,800 --> 00:03:36,720 And here we're using the ternary operator, 72 72 00:03:36,720 --> 00:03:41,720 then return the bill value, times zero point 15. 73 73 00:03:41,800 --> 00:03:43,470 So that's 15%. 74 74 00:03:43,470 --> 00:03:47,743 And otherwise, it should be 20%. 75 75 00:03:49,790 --> 00:03:53,910 Okay, so the result of this ternary operator here 76 76 00:03:53,910 --> 00:03:56,520 will be one of these values. 77 77 00:03:56,520 --> 00:04:01,030 So either bill times point 15 or times point two. 78 78 00:04:01,030 --> 00:04:04,260 And so that's gonna be the result of this operator. 79 79 00:04:04,260 --> 00:04:06,733 And so that's what this function will return. 80 80 00:04:08,560 --> 00:04:12,280 If you prefer the arrow function, we can also do that. 81 81 00:04:12,280 --> 00:04:17,280 So const calcTip equal bill. 82 82 00:04:19,500 --> 00:04:22,330 And now we can omit the return keyword 83 83 00:04:22,330 --> 00:04:24,603 and do it all in one nice line. 84 84 00:04:25,890 --> 00:04:29,860 So now you just have to choose which one you like better. 85 85 00:04:29,860 --> 00:04:32,683 And I will just for the sake of readability. 86 86 00:04:33,640 --> 00:04:36,100 Keep the first one there. Okay. 87 87 00:04:36,100 --> 00:04:37,890 But if you prefer the arrow function, 88 88 00:04:37,890 --> 00:04:41,260 you can just use this one. Great. 89 89 00:04:41,260 --> 00:04:45,530 So number two is to simply create a bills array 90 90 00:04:45,530 --> 00:04:47,333 with these three values. 91 91 00:04:50,610 --> 00:04:55,610 So bills 125, five five five and 44. 92 92 00:04:57,890 --> 00:04:59,760 So that was easy. 93 93 00:04:59,760 --> 00:05:04,150 And now we will create an array tips, 94 94 00:05:04,150 --> 00:05:06,963 which will contain the tip value for each bill. 95 95 00:05:09,150 --> 00:05:11,203 So, let's do that. 96 96 00:05:12,110 --> 00:05:14,410 And now this is similar to what we did previously 97 97 00:05:14,410 --> 00:05:16,490 with calculating the ages. 98 98 00:05:16,490 --> 00:05:19,100 So we are going to create an array, 99 99 00:05:19,100 --> 00:05:23,470 and then each position will be the function call to calcTip. 100 100 00:05:24,760 --> 00:05:29,760 So we want to calc the tip with bills at position zero. 101 101 00:05:31,310 --> 00:05:35,233 Then at position one, we want to calculate bills. 102 102 00:05:36,410 --> 00:05:39,550 Or we actually want to calculate tips based on bills 103 103 00:05:39,550 --> 00:05:44,550 on position one, and then on position two. And that's it. 104 104 00:05:48,780 --> 00:05:50,820 So let's log both the bills 105 105 00:05:52,560 --> 00:05:54,733 and the tips to the console here. 106 106 00:05:57,960 --> 00:06:01,060 And that gives us tips is not defined. 107 107 00:06:01,060 --> 00:06:02,750 So here, it should be tips. 108 108 00:06:02,750 --> 00:06:05,260 So usually when I have an array, 109 109 00:06:05,260 --> 00:06:07,230 I like to give it a plural name, 110 110 00:06:07,230 --> 00:06:10,980 like here bills and here tips. 111 111 00:06:10,980 --> 00:06:12,983 So because it's multiple values, 112 112 00:06:14,400 --> 00:06:16,920 so now that should work. 113 113 00:06:16,920 --> 00:06:21,850 And yeah, so these were the three tips that were calculated. 114 114 00:06:21,850 --> 00:06:24,950 And of course, you could have created separate values, 115 115 00:06:24,950 --> 00:06:26,980 or actually separate variables 116 116 00:06:26,980 --> 00:06:28,970 for each of these function calls, 117 117 00:06:28,970 --> 00:06:33,970 like tip one equals calcTip with bills, zero, 118 118 00:06:35,560 --> 00:06:36,620 something like this. 119 119 00:06:36,620 --> 00:06:38,530 And then tip two and tip three. 120 120 00:06:38,530 --> 00:06:41,180 And then you could have created 121 121 00:06:41,180 --> 00:06:45,753 like an array with tip one, tip two and tip three. 122 122 00:06:47,330 --> 00:06:49,280 Okay, so something like this. 123 123 00:06:49,280 --> 00:06:53,070 But my idea was to actually do it like this, 124 124 00:06:53,070 --> 00:06:54,620 because then we don't have to create 125 125 00:06:54,620 --> 00:06:58,083 all these extra variables. So that's a lot cleaner. 126 126 00:07:00,380 --> 00:07:01,810 Later on in the section, 127 127 00:07:01,810 --> 00:07:04,840 we will find an even better way of doing this. 128 128 00:07:04,840 --> 00:07:07,110 But with what we know, at this point, 129 129 00:07:07,110 --> 00:07:09,033 this is the best that we can do. 130 130 00:07:10,030 --> 00:07:12,330 So we take the first bill, 131 131 00:07:12,330 --> 00:07:14,700 calculate the tip based on that 132 132 00:07:14,700 --> 00:07:18,280 and put it in position number zero, 133 133 00:07:18,280 --> 00:07:21,710 then we take bills at position number one 134 134 00:07:21,710 --> 00:07:24,420 calculate the tip and put it in position one 135 135 00:07:24,420 --> 00:07:25,790 of this new array, 136 136 00:07:25,790 --> 00:07:29,450 and then we take bills at position number two, 137 137 00:07:29,450 --> 00:07:30,590 calculate the tip 138 138 00:07:30,590 --> 00:07:33,773 and put it at position two of the new array. 139 139 00:07:35,270 --> 00:07:39,043 And so then, now we end up with this. 140 140 00:07:41,810 --> 00:07:44,970 Lastly, let's also complete the bonus question 141 141 00:07:44,970 --> 00:07:46,540 number four here. 142 142 00:07:46,540 --> 00:07:49,870 And all you have to do here is to create an array, 143 143 00:07:49,870 --> 00:07:53,573 which will have the sum of the bills and the tips. 144 144 00:07:55,400 --> 00:07:57,663 So that's gonna be totals. 145 145 00:07:59,260 --> 00:08:03,670 And now you might have tried to do something like this. 146 146 00:08:03,670 --> 00:08:07,430 So like bills plus tips. 147 147 00:08:07,430 --> 00:08:11,260 But as I told you in the previous lecture, 148 148 00:08:11,260 --> 00:08:13,100 this is simply not gonna work. 149 149 00:08:13,100 --> 00:08:16,640 So we cannot do any operations on arrays like this, 150 150 00:08:16,640 --> 00:08:18,033 it doesn't work like that. 151 151 00:08:19,520 --> 00:08:22,020 So let me show you the result that we would get 152 152 00:08:22,020 --> 00:08:23,073 from doing this. 153 153 00:08:25,040 --> 00:08:28,120 And so basically, each of the arrays would be transformed 154 154 00:08:28,120 --> 00:08:31,843 to a string, and then the two strings would be concatenated. 155 155 00:08:33,490 --> 00:08:36,380 So that's completely useless. 156 156 00:08:36,380 --> 00:08:39,260 And so the only thing that we could do 157 157 00:08:39,260 --> 00:08:44,260 is to say that we want bills at position zero, 158 158 00:08:44,370 --> 00:08:48,453 plus the tips at position zero. 159 159 00:08:50,480 --> 00:08:55,173 And now we do this for all the three values. 160 160 00:08:57,660 --> 00:08:59,670 So at position one as well. 161 161 00:08:59,670 --> 00:09:03,813 And then at position two. 162 162 00:09:04,690 --> 00:09:08,700 And so this fixes this error, because now in each position, 163 163 00:09:08,700 --> 00:09:10,990 we do actually have a real value, 164 164 00:09:10,990 --> 00:09:13,460 because this is an actual value. 165 165 00:09:13,460 --> 00:09:16,653 And so with that, we can then do calculations. 166 166 00:09:18,400 --> 00:09:23,400 So, yeah, this is correct. Looks correct. Right. 167 167 00:09:25,740 --> 00:09:30,340 And yeah, so with that, all of the four points are solved. 168 168 00:09:30,340 --> 00:09:33,540 And so here we conclude this part about arrays 14464