1 00:00:00,240 --> 00:00:05,550 All right, in this lesson, we've got kind of a two part where we've got includes and ternary operator 2 00:00:05,670 --> 00:00:07,710 and we want to put them together within the challenge. 3 00:00:07,950 --> 00:00:13,260 So includes as a method that determines whether an array includes a certain value amongst its entries 4 00:00:13,590 --> 00:00:16,560 returning true or false as appropriate. 5 00:00:16,770 --> 00:00:23,670 And so this is perfect for ternary operator because we can check to see if this boolean value is true 6 00:00:23,670 --> 00:00:29,100 or false and then apply a different outcome depending on what that is. 7 00:00:29,220 --> 00:00:32,950 So ternary is short form for a conditional operator. 8 00:00:32,950 --> 00:00:34,770 It allows you to do it within one statement. 9 00:00:34,960 --> 00:00:38,070 It expects takes in the three different operands. 10 00:00:38,310 --> 00:00:42,570 And the first one is going to be the Bulleen response to the condition. 11 00:00:42,780 --> 00:00:47,670 And then if it's true, it's going to give you one output and if it's false, it's going to give you 12 00:00:47,670 --> 00:00:48,420 another output. 13 00:00:48,720 --> 00:00:54,440 And they've got an example of how the territory will work over here and especially within a function. 14 00:00:54,480 --> 00:00:57,330 This is really useful because it's going to be returning back. 15 00:00:57,450 --> 00:00:59,970 If is a member, then it's going to be two bucks. 16 00:01:00,180 --> 00:01:03,720 And if it's not a member, then it's going to be ten dollars. 17 00:01:04,320 --> 00:01:11,100 So sending in either true false or one is going to have different results being returned back. 18 00:01:11,340 --> 00:01:17,070 And in this case, this is where we can use that includes because this will return back either true 19 00:01:17,340 --> 00:01:23,880 or false within the statement, let's create a temporary array and we could just add in some random 20 00:01:23,880 --> 00:01:24,870 values in here. 21 00:01:25,260 --> 00:01:32,220 We're going to use includes so we indicate what array and then use that includes method in order to 22 00:01:32,220 --> 00:01:36,240 determine what value we're looking for that we want to include. 23 00:01:36,360 --> 00:01:39,360 So we want to see if that array includes five. 24 00:01:39,750 --> 00:01:40,530 Let's refresh. 25 00:01:40,640 --> 00:01:41,990 We see that the outcome is true. 26 00:01:42,420 --> 00:01:44,250 Also, let's look for six. 27 00:01:44,250 --> 00:01:45,210 We also have true. 28 00:01:45,420 --> 00:01:47,160 What if it's 64? 29 00:01:47,340 --> 00:01:48,930 We get a result back of false. 30 00:01:48,960 --> 00:01:49,910 So it doesn't include that. 31 00:01:50,340 --> 00:01:51,900 So you get a boolean response. 32 00:01:52,110 --> 00:01:59,520 And similar to what we were looking at, index of within arrays as well that we can check to see if 33 00:01:59,520 --> 00:02:04,550 it includes set and if it doesn't if it's not within the array, then we got a negative one back. 34 00:02:04,560 --> 00:02:06,690 Otherwise we got the index value. 35 00:02:06,840 --> 00:02:09,480 And in this case, this is how we can return a bullet value. 36 00:02:09,630 --> 00:02:11,480 Let's create one other quick function. 37 00:02:11,520 --> 00:02:16,770 So wrap it within rounded brackets and we're checking to see if the value is true. 38 00:02:16,860 --> 00:02:19,920 And if it is true, then we're going to return back. 39 00:02:19,920 --> 00:02:20,370 Yes. 40 00:02:20,370 --> 00:02:21,910 And separate it with the colon. 41 00:02:21,960 --> 00:02:26,220 Otherwise we're going to return back so we can try that that function. 42 00:02:26,580 --> 00:02:28,200 So passing in a boolean value. 43 00:02:28,210 --> 00:02:31,470 So, yes, another boolean value of false returns back. 44 00:02:31,470 --> 00:02:31,830 No. 45 00:02:32,040 --> 00:02:33,960 So we can combine these together now. 46 00:02:34,230 --> 00:02:42,330 So instead of looking to see that includes we can check to see if that value that we're passing in is 47 00:02:42,330 --> 00:02:46,400 in the array and if it is then we're going to get includes, otherwise we're not. 48 00:02:46,650 --> 00:02:52,430 So if we passed in five, we see five is there, 66 is no and so on. 49 00:02:52,470 --> 00:02:57,030 So we can pass in any of the values and if it's in the array then we get return back. 50 00:02:57,420 --> 00:02:58,010 Yes. 51 00:02:58,020 --> 00:02:59,520 Otherwise we get return back. 52 00:02:59,520 --> 00:03:01,650 No, if it's not, if it's not within the array. 53 00:03:01,680 --> 00:03:07,440 So this lesson challenge, we're going to use what we just learned and take that and apply that to generate 54 00:03:07,440 --> 00:03:10,800 50 random numbers from one to twenty. 55 00:03:11,010 --> 00:03:14,910 And we're going to exclude these values from that list. 56 00:03:14,910 --> 00:03:21,990 So 10, 15, seven one, four, two and five are not included within the response of that random number. 57 00:03:22,170 --> 00:03:25,640 So using a function and output the results into the console. 58 00:03:25,890 --> 00:03:31,110 So within their console, you're going to see a listing of all the numbers, but you can't return back 59 00:03:31,110 --> 00:03:36,450 the ones that are within the list and you can use recursion within the function in order to accomplish 60 00:03:36,450 --> 00:03:37,140 this as well. 61 00:03:37,320 --> 00:03:42,810 I'll give you a quick sneak peek at the code that we're going to be using and pause the video here and 62 00:03:42,810 --> 00:03:45,810 I'll walk you through how you can set this up coming up. 63 00:03:45,960 --> 00:03:46,100 Okay. 64 00:03:46,200 --> 00:03:47,520 So have you had an opportunity? 65 00:03:47,550 --> 00:03:50,370 So first thing that we need is we need to have an array. 66 00:03:50,580 --> 00:03:56,370 So this is our exclude numbers array and these are all the numbers that we're excluding. 67 00:03:56,550 --> 00:03:58,230 And they can be any numbers. 68 00:03:58,230 --> 00:03:59,840 I'm just picking some at random. 69 00:04:00,060 --> 00:04:06,180 We're also going to need a function that's going to generate random number and passing in a minimum 70 00:04:06,180 --> 00:04:07,210 and a maximum. 71 00:04:07,230 --> 00:04:09,330 So it's completely flexible and dynamic. 72 00:04:09,330 --> 00:04:13,320 First, that random number Samarth floor. 73 00:04:13,350 --> 00:04:19,200 So using the math object on at random in order to get a random number, no other way, and then selecting 74 00:04:19,200 --> 00:04:24,750 from that random, we're taking the max minus the men plus one. 75 00:04:24,750 --> 00:04:27,180 And we're also going to add in the one to that. 76 00:04:27,270 --> 00:04:31,170 And for now, let's return back to number and we do need an equal sign in there. 77 00:04:31,290 --> 00:04:32,070 So just save that. 78 00:04:32,610 --> 00:04:40,060 So now we can try that or generate random and then our minimum can be one and the maximum is four. 79 00:04:40,110 --> 00:04:45,140 So every time we post that, you see we can get a random number from one to four. 80 00:04:45,180 --> 00:04:49,540 We saw that we can generate any one of those numbers at random using the formula. 81 00:04:49,860 --> 00:04:53,670 So the next thing that we want it to do is have 20 iterations of that. 82 00:04:54,060 --> 00:04:57,210 So setting that up, setting X is equal to zero. 83 00:04:57,480 --> 00:04:59,910 And we're going to just do a typical Falu and then. 84 00:04:59,950 --> 00:05:05,860 Increment X so that we have a way out of the loop and then we can console log whatever number is being 85 00:05:05,860 --> 00:05:10,010 returned back from that formula and we're going to have our minimum value. 86 00:05:10,060 --> 00:05:15,470 So setting the minimum at 1:00 and setting the max is equal to 15. 87 00:05:15,490 --> 00:05:19,410 And this is where we're going to use that formula where we've got generating random. 88 00:05:19,600 --> 00:05:21,730 So you could also just hardcoded in. 89 00:05:21,730 --> 00:05:26,140 But this makes it a little bit more flexible, of course, to see now that we're generating all of these 90 00:05:26,140 --> 00:05:29,370 random numbers anywhere from one to 15. 91 00:05:29,380 --> 00:05:30,460 So it could be any of them. 92 00:05:30,490 --> 00:05:33,490 Every time we refresh, you see we've got another set of numbers there. 93 00:05:33,640 --> 00:05:35,140 So there's one there's 15. 94 00:05:35,260 --> 00:05:37,590 There's no numbers that are outside of that spectrum. 95 00:05:37,900 --> 00:05:39,520 So that part is working great. 96 00:05:39,790 --> 00:05:42,850 And the next thing that we need to do is exclude numbers. 97 00:05:43,120 --> 00:05:47,530 So instead of just returning the number, we're going to do something a little bit more complex where 98 00:05:47,530 --> 00:05:55,420 we want to get the result using the X numbers and then using includes and checking to see if that number 99 00:05:55,420 --> 00:05:56,240 is there. 100 00:05:56,740 --> 00:06:03,040 So that means that if that one of these numbers is one of the ones that we potentially might be returning, 101 00:06:03,190 --> 00:06:04,920 we don't want to return it quite yet. 102 00:06:05,260 --> 00:06:08,380 And what we want to do instead is we want to generate a new number. 103 00:06:08,860 --> 00:06:14,980 So we're passing again into that generate random so creating recursion within the function where we're 104 00:06:14,980 --> 00:06:22,540 going to generate another random number until we are able to return one that isn't within the array. 105 00:06:22,540 --> 00:06:26,500 Otherwise we can just return back the number we can refresh. 106 00:06:26,770 --> 00:06:29,960 And now you can see that we're excluding all of those numbers. 107 00:06:29,980 --> 00:06:36,430 So no matter how many times we run it, we're never going to see one to four or five, seven, 10 or 108 00:06:36,430 --> 00:06:38,650 15 within the returned numbers. 109 00:06:38,890 --> 00:06:44,290 And you can shorten this as well as just doing a simple return here so you don't have to use the other 110 00:06:44,740 --> 00:06:45,340 variable. 111 00:06:45,560 --> 00:06:46,660 So it's going to do the same thing. 112 00:06:46,840 --> 00:06:51,040 And before we conclude, the challenge was any number from one to 20. 113 00:06:51,250 --> 00:06:56,130 So that's why it's good that we did set up the variables because we can update our Macs really easily. 114 00:06:56,140 --> 00:07:00,820 And now you can see that we're getting any number from one to 20, but we're excluding the ones that 115 00:07:00,820 --> 00:07:02,200 are within the array.