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These are the user uploaded subtitles that are being translated: 1 1 00:00:01,260 --> 00:00:04,040 It's now time for your final coding challenge 2 2 00:00:04,040 --> 00:00:05,620 in this section. 3 3 00:00:05,620 --> 00:00:07,820 And this one is gonna allow you to assess 4 4 00:00:07,820 --> 00:00:09,570 whether you actually understood 5 5 00:00:09,570 --> 00:00:11,760 how the ternary operator works. 6 6 00:00:11,760 --> 00:00:15,200 So it's gonna be really fun and actually really short. 7 7 00:00:15,200 --> 00:00:16,993 So let's do that now. 8 8 00:00:18,610 --> 00:00:20,060 And here it goes, 9 9 00:00:20,060 --> 00:00:23,930 so Steven wants to build a very simple tip calculator 10 10 00:00:23,930 --> 00:00:27,240 for whenever he goes eating in a restaurant. 11 11 00:00:27,240 --> 00:00:31,040 Now in his country, it's usual to tip 15% 12 12 00:00:31,040 --> 00:00:35,290 if the bill value is between 50 and 300. 13 13 00:00:35,290 --> 00:00:37,010 And if the value is different, 14 14 00:00:37,010 --> 00:00:41,170 so if it's not between this range between 50 and 300, 15 15 00:00:41,170 --> 00:00:43,920 then the tip is usually 20%. 16 16 00:00:43,920 --> 00:00:46,320 So your task is to calculate the tip 17 17 00:00:46,320 --> 00:00:48,270 depending on the bill value, 18 18 00:00:48,270 --> 00:00:51,450 according to the rules that I just mentioned, 19 19 00:00:51,450 --> 00:00:55,230 and to do this, you will create a variable called tip, 20 20 00:00:55,230 --> 00:00:57,970 which is then gonna store the tip value. 21 21 00:00:57,970 --> 00:01:00,970 And probably you should also create a bill variable 22 22 00:01:00,970 --> 00:01:03,590 which just gonna hold the test data. 23 23 00:01:03,590 --> 00:01:07,637 So first 275, 1040, and then 430. 24 24 00:01:08,930 --> 00:01:11,540 So you should test your bill calculator 25 25 00:01:11,540 --> 00:01:13,480 for these three bill values. 26 26 00:01:13,480 --> 00:01:17,630 Okay, now what's important here is that it's not allowed 27 27 00:01:17,630 --> 00:01:21,150 to use an if else statement, all right. 28 28 00:01:21,150 --> 00:01:23,290 Now, if it's easier for you, 29 29 00:01:23,290 --> 00:01:27,150 you can first do this calculation using an if else statement 30 30 00:01:27,150 --> 00:01:30,340 and then convert that to a ternary operator, 31 31 00:01:30,340 --> 00:01:33,350 but the final solution should not contain 32 32 00:01:33,350 --> 00:01:36,230 the if else statement, okay. 33 33 00:01:36,230 --> 00:01:38,040 Then once you have to calculate it, 34 34 00:01:38,040 --> 00:01:39,850 print a string to the console, 35 35 00:01:39,850 --> 00:01:43,940 which will contain the initial bill value, the tip value, 36 36 00:01:43,940 --> 00:01:46,190 and also the final value. 37 37 00:01:46,190 --> 00:01:49,410 So that's gonna be the bill plus the tip 38 38 00:01:49,410 --> 00:01:53,680 and as an example, for example, when the bill is 275, 39 39 00:01:53,680 --> 00:01:58,290 the output string will be like this, okay. 40 40 00:01:58,290 --> 00:02:00,820 So once more, I hope you managed to do this 41 41 00:02:00,820 --> 00:02:04,020 and actually I have two hints to help you solving this, 42 42 00:02:04,020 --> 00:02:07,220 but if you want to try this on your own without the hints, 43 43 00:02:07,220 --> 00:02:09,670 line:15% then just pause the video right now. 44 44 00:02:09,670 --> 00:02:13,363 line:15% But if you actually need to hints, then well, here they go. 45 45 00:02:14,280 --> 00:02:18,090 So to calculate, for example, 20% of a value, 46 46 00:02:18,090 --> 00:02:21,610 all you need to do is to multiply the value by 20 47 47 00:02:21,610 --> 00:02:25,223 divided by 100, which is 0.2. 48 48 00:02:26,720 --> 00:02:29,290 So multiply it, okay. 49 49 00:02:29,290 --> 00:02:32,390 So that's how we calculate the percentage of a value, 50 50 00:02:32,390 --> 00:02:34,970 which you need here for these rules. 51 51 00:02:34,970 --> 00:02:38,460 So 15% and 20% 52 52 00:02:38,460 --> 00:02:40,410 Now as a second hint, 53 53 00:02:40,410 --> 00:02:44,370 to check whether the value is between 50 and 300, 54 54 00:02:44,370 --> 00:02:49,370 you do basically this comparison. 55 55 00:02:49,780 --> 00:02:53,350 So it needs to be greater or equal than 50, 56 56 00:02:53,350 --> 00:02:56,290 and it needs to be less or equal 300. 57 57 00:02:56,290 --> 00:03:01,290 That's what it means to be between 50 and 300, okay. 58 58 00:03:01,600 --> 00:03:02,940 And with these two hints 59 59 00:03:02,940 --> 00:03:04,920 and the knowledge from the last lecture, 60 60 00:03:04,920 --> 00:03:07,430 I really hope that you manage to implement 61 61 00:03:07,430 --> 00:03:09,560 this simple tip calculator. 62 62 00:03:09,560 --> 00:03:12,343 line:15% So pause the video now and I see you in a second. 63 63 00:03:15,480 --> 00:03:20,480 line:15% Okay, so I hope you successfully did that 64 64 00:03:22,360 --> 00:03:25,043 and so let's try to solve it now together, 65 65 00:03:26,430 --> 00:03:29,290 or actually let me show you my solution 66 66 00:03:29,290 --> 00:03:32,400 so that you can see how it compares with yours. 67 67 00:03:32,400 --> 00:03:34,870 And as always, you can also find my solution 68 68 00:03:34,870 --> 00:03:38,713 in the final folder, in the GitHub repository, okay. 69 69 00:03:40,410 --> 00:03:45,090 Now actually let's start with the bill variable, 70 70 00:03:45,090 --> 00:03:47,940 which I'm gonna set to 275, 71 71 00:03:47,940 --> 00:03:50,313 which is here the first test value, 72 72 00:03:51,780 --> 00:03:54,900 and now the tip and let's calculate it 73 73 00:03:54,900 --> 00:03:56,603 using the ternary operator. 74 74 00:03:58,670 --> 00:04:00,750 So, let's implement this rule, 75 75 00:04:00,750 --> 00:04:04,452 which is if the value is between 50 and 300, 76 76 00:04:04,452 --> 00:04:08,363 then the tip should be 15% of the bill value. 77 77 00:04:11,730 --> 00:04:16,730 So that means that bill must be less or equal 300, 78 78 00:04:19,660 --> 00:04:24,660 and at the same time, bill must be greater or equal than 50. 79 79 00:04:28,190 --> 00:04:32,040 Right, and again, that's what it means for the bill value 80 80 00:04:32,040 --> 00:04:35,490 to be between 300 and 50. 81 81 00:04:35,490 --> 00:04:37,760 It's gonna be less or equal 300, 82 82 00:04:37,760 --> 00:04:42,760 and at the same time, greater or equal than 50. 83 83 00:04:42,830 --> 00:04:46,330 So 40 for example is of course less than 300, 84 84 00:04:46,330 --> 00:04:48,840 but it's also less than 50 85 85 00:04:48,840 --> 00:04:51,440 and so this part here will then be false. 86 86 00:04:51,440 --> 00:04:54,090 and so this entire expression here, 87 87 00:04:54,090 --> 00:04:57,963 which is stand true and false will be false as well. 88 88 00:04:58,960 --> 00:05:01,580 Right, so in this case, 89 89 00:05:01,580 --> 00:05:06,333 the tip here will be the bill value times 15%, 90 90 00:05:08,690 --> 00:05:10,713 which as I explained here, 91 91 00:05:11,730 --> 00:05:15,630 all we need to do is to multiply it by 15 divided by 100. 92 92 00:05:15,630 --> 00:05:20,560 So that 0.15 and else it's 20%. 93 93 00:05:22,410 --> 00:05:27,410 So bill times 0.2, give it a safe and that's actually it. 94 94 00:05:29,790 --> 00:05:31,003 So that's number one. 95 95 00:05:33,100 --> 00:05:35,210 And now as number two, 96 96 00:05:35,210 --> 00:05:38,550 let's lock the string to the console 97 97 00:05:38,550 --> 00:05:41,390 as is requested here in number two. 98 98 00:05:41,390 --> 00:05:44,530 So let's actually grab this template here 99 99 00:05:44,530 --> 00:05:47,420 so then we just have to replace the values, 100 100 00:05:47,420 --> 00:05:49,960 and so since we're building a string, we are again, 101 101 00:05:49,960 --> 00:05:52,113 relying on the template literal. 102 102 00:05:53,660 --> 00:05:55,700 So here we're gonna put the bill value 103 103 00:05:58,810 --> 00:06:00,970 here we're gonna put the tip 104 104 00:06:02,300 --> 00:06:04,430 and we're missing the curly braces 105 105 00:06:04,430 --> 00:06:09,430 and here the total value is gonna be the bill plus the tip. 106 106 00:06:10,410 --> 00:06:12,510 So we can, as you already know, 107 107 00:06:12,510 --> 00:06:17,230 write an expression here using this operator 108 108 00:06:17,230 --> 00:06:18,503 so the plus operator, 109 109 00:06:20,470 --> 00:06:22,270 and that's actually it. 110 110 00:06:22,270 --> 00:06:25,310 So let's try it and with this bill value, 111 111 00:06:25,310 --> 00:06:27,970 the output should actually be exactly 112 112 00:06:27,970 --> 00:06:32,110 like it's written up there and it is. 113 113 00:06:32,110 --> 00:06:37,110 So 275, the tip is a 4125, so just like here 114 114 00:06:37,480 --> 00:06:41,053 and the total value is 316.25. 115 115 00:06:41,890 --> 00:06:45,000 Great, and just to understand this one, 116 116 00:06:45,000 --> 00:06:46,890 so this condition a little bit better, 117 117 00:06:46,890 --> 00:06:50,823 let's just take this one and paste it here into the console. 118 118 00:06:51,870 --> 00:06:54,340 And so we see that this one is true 119 119 00:06:54,340 --> 00:06:58,644 and of course that's because 275 is less than 300 120 120 00:06:58,644 --> 00:07:00,330 and more than 50. 121 121 00:07:00,330 --> 00:07:03,210 So it is between this range and therefore 122 122 00:07:03,210 --> 00:07:07,070 this part of the ternary operator here will be executed 123 123 00:07:07,070 --> 00:07:10,430 and to become the result of this operator, essentially. 124 124 00:07:10,430 --> 00:07:13,100 Right, so the result of this operator 125 125 00:07:13,100 --> 00:07:16,870 will be bill times 0.15 and that's the value 126 126 00:07:16,870 --> 00:07:21,560 that will then be assigned to the tip variable, okay. 127 127 00:07:21,560 --> 00:07:23,090 Now let's try another one. 128 128 00:07:23,090 --> 00:07:28,090 So 40, and now the tip was eight. 129 129 00:07:30,500 --> 00:07:32,043 Let's try this one here again, 130 130 00:07:33,350 --> 00:07:35,430 and now the condition is false. 131 131 00:07:35,430 --> 00:07:37,460 So remember that here in the console, 132 132 00:07:37,460 --> 00:07:39,330 we have access to all the variables 133 133 00:07:39,330 --> 00:07:41,170 that we have declared here. 134 134 00:07:41,170 --> 00:07:45,210 So if I write bill now, you will see that it's actually 40. 135 135 00:07:45,210 --> 00:07:50,163 So bill is obviously below 300, but it's also below 50. 136 136 00:07:51,330 --> 00:07:55,600 So this part is false and true and false gives false. 137 137 00:07:55,600 --> 00:07:57,500 And so in this case, the value 138 138 00:07:57,500 --> 00:08:02,320 that's gonna be assigned to tip is 40 times 0.2 139 139 00:08:02,320 --> 00:08:04,320 and that's exactly eight. 140 140 00:08:04,320 --> 00:08:07,000 So it's what we see here. 141 141 00:08:07,000 --> 00:08:10,100 Okay, and now just for the sake of completion, 142 142 00:08:10,100 --> 00:08:11,640 let's do the last one as well 143 143 00:08:14,370 --> 00:08:18,360 and now this should have worked as well 144 144 00:08:18,360 --> 00:08:21,787 because now this one is false again 145 145 00:08:21,787 --> 00:08:26,360 and that's because this time 430 is above 300 146 146 00:08:26,360 --> 00:08:31,360 and so 86 should be 430 times 0.2. 147 147 00:08:32,570 --> 00:08:37,280 Let's quickly check that 0.2 and that's right. 148 148 00:08:37,280 --> 00:08:39,603 That's the 86 that we have up here. 149 149 00:08:40,620 --> 00:08:44,930 Great, so hopefully you did this and once more, 150 150 00:08:44,930 --> 00:08:46,597 if you did it a little bit differently, 151 151 00:08:46,597 --> 00:08:48,530 that's not a problem at all. 152 152 00:08:48,530 --> 00:08:51,890 I just hope that you made it work, okay. 153 153 00:08:51,890 --> 00:08:55,750 And actually this concludes the coding part of this section 154 154 00:08:55,750 --> 00:08:57,810 there's just one more lecture left, 155 155 00:08:57,810 --> 00:09:01,580 which is going to be a deeper dive into JavaScript versions, 156 156 00:09:01,580 --> 00:09:04,690 especially into and ES5 and ES6. 157 157 00:09:04,690 --> 00:09:08,180 So it's gonna be an interesting one and yeah, 158 158 00:09:08,180 --> 00:09:09,480 I'm waiting for you there. 13783