1 00:00:08,080 --> 00:00:10,750 Hey everybody this is Caleb with slopes dot com. 2 00:00:10,750 --> 00:00:14,500 And in this video we're going to be talking about enumerations. 3 00:00:14,500 --> 00:00:18,130 Enumerations are a really cool thing and swift. 4 00:00:18,130 --> 00:00:24,400 It's a type that basically contains a group of related values that are all kind of under the same umbrella 5 00:00:24,700 --> 00:00:25,620 as each other. 6 00:00:25,870 --> 00:00:31,120 So if you think about like a you know car is the big umbrella you might have Maserati Lamborghini Geo 7 00:00:31,120 --> 00:00:32,060 Metro. 8 00:00:32,230 --> 00:00:36,630 Nice if you think about fruit you might have banana apple orange. 9 00:00:36,630 --> 00:00:43,170 They're all related values under the same overarching type which is you know a cool way to manage it. 10 00:00:43,450 --> 00:00:49,990 And basically what an enumeration allows us to do is we can work with those values in a type safe way 11 00:00:50,470 --> 00:00:51,540 which is really neat. 12 00:00:51,640 --> 00:00:56,680 So to show you how this works I'm actually going to go ahead and create a playground and we're going 13 00:00:56,680 --> 00:01:00,450 to go ahead and I'm going to teach you the syntax of an enumeration. 14 00:01:00,850 --> 00:01:04,900 I'm going to show you a couple different things you can do with enumerations and then at the very end 15 00:01:05,530 --> 00:01:10,180 I'm going to show you a practical example that you could actually use in an application so you know 16 00:01:10,180 --> 00:01:11,380 how you can use this. 17 00:01:11,380 --> 00:01:16,660 So let's go ahead and click get started with a playground and that should pop up popped up on my other 18 00:01:16,660 --> 00:01:17,470 window here. 19 00:01:17,560 --> 00:01:24,610 But for now let's create a blank playground and I'm just going to name it know as teacher because I'm 20 00:01:24,610 --> 00:01:25,210 the teacher. 21 00:01:25,210 --> 00:01:30,260 You can name it whatever you want and go ahead and bump that open into full screen. 22 00:01:30,790 --> 00:01:32,580 And we're going to go ahead. 23 00:01:32,780 --> 00:01:33,220 You know what. 24 00:01:33,220 --> 00:01:37,660 This might be an ex code beta but it looks like we're not going to be able to stretch that any wider 25 00:01:37,690 --> 00:01:38,810 but that's fine. 26 00:01:38,830 --> 00:01:44,110 So for now let's get rid of that string there we don't need it let's get rid of the boilerplate code 27 00:01:44,710 --> 00:01:46,420 and let's begin. 28 00:01:46,420 --> 00:01:52,350 So the syntax of an enumeration goes like this you declare it by typing inam. 29 00:01:52,420 --> 00:01:54,410 OK that's short for enumeration. 30 00:01:54,820 --> 00:02:00,120 And then you give it a name and think of these names like you would name a class. 31 00:02:00,130 --> 00:02:04,480 OK so you're going to use capital letters at the very beginning for every word. 32 00:02:04,480 --> 00:02:05,770 It will have a capital. 33 00:02:05,770 --> 00:02:14,040 So just for example name of income and then you're going to give it some curly braces just like a class. 34 00:02:14,080 --> 00:02:19,870 Now inside an enumeration we're going to go ahead and we're going to set up cases. 35 00:02:19,870 --> 00:02:20,420 OK. 36 00:02:20,680 --> 00:02:26,620 If you've ever used a switch statement you're familiar with these a switch basically allows you to go 37 00:02:26,620 --> 00:02:31,750 through a bunch of different options and you call each one of those options a case. 38 00:02:31,750 --> 00:02:37,930 And so for an enumeration we're going to give it cases as well so I'm just going to say Case case one 39 00:02:38,590 --> 00:02:43,200 case case to case case three. 40 00:02:43,270 --> 00:02:43,600 OK. 41 00:02:43,630 --> 00:02:47,250 Now of course these would be named something differently in a different enumeration. 42 00:02:47,260 --> 00:02:48,980 But for now this is just an example. 43 00:02:49,210 --> 00:02:53,600 And as you can see the enumeration has three separate cases. 44 00:02:53,770 --> 00:03:02,620 And in order to instantiate that all you need to do is to set up let in numeration and we can make it 45 00:03:02,680 --> 00:03:03,720 of type. 46 00:03:04,060 --> 00:03:08,230 Well actually let's do a colon there make it of type name of a name. 47 00:03:08,230 --> 00:03:12,520 This of course is a terrible name but it's just for an example I'll show you some real examples in a 48 00:03:12,520 --> 00:03:13,510 second. 49 00:03:13,510 --> 00:03:16,710 And we can set that to be equal to one of our cases. 50 00:03:16,780 --> 00:03:19,970 OK and I'll show you why this is useful in just a little bit. 51 00:03:20,110 --> 00:03:23,800 Now to actually access these cases I can't just type case one. 52 00:03:23,800 --> 00:03:25,040 You'll see it doesn't pop up. 53 00:03:25,270 --> 00:03:31,630 But what I can do is I can type a period and that will give me access to all three of the different 54 00:03:31,630 --> 00:03:32,590 cases that I've set. 55 00:03:32,590 --> 00:03:35,230 So let's set this to be equal to case two. 56 00:03:35,470 --> 00:03:39,310 And now you can see its value on the screen there is set to be case too. 57 00:03:39,560 --> 00:03:41,130 OK that's pretty cool. 58 00:03:41,140 --> 00:03:47,220 So this is the basic syntax of an enumeration you declare with ENM and you'd give it cases. 59 00:03:47,350 --> 00:03:47,940 OK. 60 00:03:48,130 --> 00:03:55,930 Like I said before Karr could be the name of the enim and the cases could be DeLorean Maserati Lamborghini 61 00:03:56,170 --> 00:03:58,120 Cato's could be all the different cases. 62 00:03:58,210 --> 00:04:01,750 Now you don't have to declare each case on a separate line. 63 00:04:01,750 --> 00:04:04,400 You can actually just go ahead and use commas. 64 00:04:04,470 --> 00:04:04,700 OK. 65 00:04:04,710 --> 00:04:10,360 Just like when you create multiple constants or variables you can declare them in one straight line 66 00:04:10,360 --> 00:04:11,320 by using commas. 67 00:04:11,440 --> 00:04:16,750 So just type case one comma case two comma case three. 68 00:04:17,260 --> 00:04:19,900 And as you can see that works just the same. 69 00:04:20,050 --> 00:04:21,520 Ok pretty cool. 70 00:04:21,520 --> 00:04:23,890 So let's go ahead and let's move on. 71 00:04:23,890 --> 00:04:25,560 I'm going to show you some other cool things. 72 00:04:25,580 --> 00:04:27,120 Enumerations can do. 73 00:04:27,460 --> 00:04:31,560 And one of those things actually is a really great example from Apple. 74 00:04:31,690 --> 00:04:37,390 So I'm going to pull open these two barcodes here and barcodes are a great example because enumerations 75 00:04:37,390 --> 00:04:44,860 allow us to work with related values but they also are good for kind of differentiating different types 76 00:04:44,890 --> 00:04:45,720 of things. 77 00:04:45,880 --> 00:04:53,160 And so here we have a standard UPC product barcode and we also have a QR code which is used for you 78 00:04:53,170 --> 00:04:56,620 know all kinds of different things storing all kinds of different information. 79 00:04:56,620 --> 00:05:01,720 So there are very different kinds of barcodes but they are both barcodes. 80 00:05:01,810 --> 00:05:08,090 So we're going to create an enumeration for barcode but we're going to give it two cases we'll be UPC 81 00:05:08,420 --> 00:05:13,250 OK like this one here that you'd see on like the back of a box of cereal or something and then we'll 82 00:05:13,250 --> 00:05:15,250 create one for the QR code. 83 00:05:15,260 --> 00:05:21,220 So go ahead and type ENM barcode and we're going to give it two cases. 84 00:05:21,290 --> 00:05:24,660 The first case will be case UPC. 85 00:05:24,740 --> 00:05:31,700 The second will be case wups case and Q are code just like that. 86 00:05:31,760 --> 00:05:38,040 Now we're going to be able to put in associated values into this barcode enumeration. 87 00:05:38,180 --> 00:05:43,260 And what that's going to allow us to do is whenever we create an instance of barcode. 88 00:05:43,400 --> 00:05:49,490 And let's just say that we create an instance of barcode UPC will be able to pass in values that are 89 00:05:49,490 --> 00:05:54,060 associated with that and then use those later or modify them it's really cool. 90 00:05:54,260 --> 00:05:59,970 So for a UPC for a product barcode you'll notice there are four different numbers. 91 00:06:00,080 --> 00:06:07,100 Now at the beginning there is a number that denotes the specific number system k that a certain product 92 00:06:07,310 --> 00:06:08,970 might use k. 93 00:06:09,140 --> 00:06:15,350 The second set of numbers is to denote the manufacturer who makes the product. 94 00:06:15,440 --> 00:06:20,340 Third is the product name of the product value basically. 95 00:06:20,360 --> 00:06:25,070 These numbers are associated with a specific product and then at the very end there's what's called 96 00:06:25,070 --> 00:06:32,110 a check and that basically allows for the store to know whether or not the barcode was scanned successfully. 97 00:06:32,240 --> 00:06:32,750 OK. 98 00:06:33,020 --> 00:06:37,670 So there are four values and what we're going to do is we're actually going to just put a parentheses 99 00:06:37,880 --> 00:06:45,740 next to you PC and we can pass in four separate values in a couple which a couple is as you know a list 100 00:06:45,890 --> 00:06:48,470 of values unrelated or related. 101 00:06:48,590 --> 00:06:49,910 That can be either. 102 00:06:50,040 --> 00:06:54,470 Now the values in this topic are going to be related and it's actually going to just be for integers 103 00:06:55,000 --> 00:06:57,890 one for each of the separate number values and our barcode. 104 00:06:57,890 --> 00:07:03,860 So go ahead and just type into comma int and do that four times like so. 105 00:07:03,860 --> 00:07:05,210 And for the QR code. 106 00:07:05,300 --> 00:07:10,880 The cool thing is a QR code can hold all kinds of information and data actually up to like two thousand 107 00:07:10,880 --> 00:07:13,550 nine hundred fifty characters or something. 108 00:07:13,550 --> 00:07:17,570 But what we're going to do is instead of passing it multiple values we're just going to pass in one 109 00:07:17,570 --> 00:07:25,160 string value because oftentimes QR codes hold textual data K like a U R L or account information. 110 00:07:25,470 --> 00:07:25,790 OK. 111 00:07:25,790 --> 00:07:26,630 Very cool. 112 00:07:26,630 --> 00:07:32,600 So now that we have these associated values with our numeration what we're going to be able to do is 113 00:07:32,600 --> 00:07:36,680 create an instance of it and pass in those values and then we can use them later on. 114 00:07:36,680 --> 00:07:43,340 So let's go ahead and let's create a barcode by typing var product barcode and we're going to set that 115 00:07:43,340 --> 00:07:44,910 to be equal to Barka. 116 00:07:45,440 --> 00:07:51,460 And if we push the little if we get a period there we can choose UPC or QR code. 117 00:07:51,530 --> 00:07:53,590 OK let's choose a UPC for now. 118 00:07:53,870 --> 00:07:58,090 And as you can see it looks a little bit like a function where passing in values. 119 00:07:58,100 --> 00:08:04,190 And we're basically just setting them as for little temporary variables inside of this barcode. 120 00:08:04,190 --> 00:08:08,420 So let's go ahead and let's give the values from our UPC here. 121 00:08:08,420 --> 00:08:14,990 So the manufacturer is or sorry the what's it called the number system is what the manufacturer is 8 122 00:08:15,050 --> 00:08:21,720 5 9 0 9 the product number is 5 1 2 2 6 and the check number is 3. 123 00:08:21,890 --> 00:08:25,460 So that's cool and all but what if I wanted to print this out if I type. 124 00:08:25,460 --> 00:08:27,520 Print product barcode. 125 00:08:27,560 --> 00:08:28,540 Watch what happens. 126 00:08:28,560 --> 00:08:36,190 It'll print down here at the bottom in just a moment so as you can see it prints out UPC and it prints 127 00:08:36,190 --> 00:08:37,210 out our four values. 128 00:08:37,330 --> 00:08:42,490 That's pretty cool but we can't exactly access them or pull them out in any way as you see nothing pops 129 00:08:42,490 --> 00:08:44,660 up when I type a period at the end of that. 130 00:08:44,740 --> 00:08:47,380 So we can't actually access it that way. 131 00:08:47,770 --> 00:08:49,850 But check out what we can do. 132 00:08:49,960 --> 00:08:55,930 We can create a switch statement and we're going to pass our bar code in and if it is a PC we're going 133 00:08:55,930 --> 00:09:01,630 to create a temporary constant and we're going to assign four constant values to the four values in 134 00:09:01,630 --> 00:09:04,540 our PC then we can work with them and modify them. 135 00:09:04,540 --> 00:09:09,980 So let's go ahead and let's create a switch statement for product bar code OK. 136 00:09:10,060 --> 00:09:13,570 And we're going to give it to cases UPC or QR code. 137 00:09:13,780 --> 00:09:19,520 So go ahead and type case and the only thing by the way since it is of type barcode The only things 138 00:09:19,520 --> 00:09:23,390 that can be are a UPC or a QR code. 139 00:09:23,590 --> 00:09:27,520 So we're going to go ahead and create some constants here. 140 00:09:27,520 --> 00:09:32,170 So inside our switch statement here we're going to go ahead and create four constants by typing let 141 00:09:32,630 --> 00:09:33,990 dot UPC. 142 00:09:34,090 --> 00:09:40,120 So we're basically saying for a PC we're going to set four constants for these four values and to do 143 00:09:40,120 --> 00:09:46,990 that go ahead and type parentheses and just like I said we're going to type number system. 144 00:09:46,990 --> 00:09:48,170 That's the first number. 145 00:09:48,460 --> 00:09:56,430 Then the manufacturer then the product then the end is a check OK. 146 00:09:56,710 --> 00:10:02,860 Now we're using Let here and just like we did up here with the three cases on the same line by typing 147 00:10:02,860 --> 00:10:07,970 let here and number system manufacturer product check we're creating four separate constants. 148 00:10:08,170 --> 00:10:12,230 And what we're going to do is once we have those four values set we can print them out. 149 00:10:12,250 --> 00:10:22,330 So print and whoops we're going to go ahead and print UPC and then using string interpolation we're 150 00:10:22,380 --> 00:10:29,110 gonna go ahead and pass these four constants we've created in and see if the values get properly passed. 151 00:10:29,110 --> 00:10:35,080 So inside of our special string interpolation syntax go ahead and type number system and then you know 152 00:10:35,080 --> 00:10:35,220 what. 153 00:10:35,230 --> 00:10:40,870 Let's actually before we type that let's copy and paste this so we don't have to type it so many times. 154 00:10:40,870 --> 00:10:41,330 There we go. 155 00:10:41,350 --> 00:10:43,260 So let's print number system. 156 00:10:43,630 --> 00:10:48,600 OK then let's print manufacturer then product. 157 00:10:48,920 --> 00:10:52,510 Whoops you know what let's call that product code. 158 00:10:52,510 --> 00:10:56,200 Actually I like that better product code. 159 00:10:56,260 --> 00:10:58,450 And at the end we're going to print the check value. 160 00:10:58,510 --> 00:11:03,700 So watch what happens when this runs through it says that it has failed. 161 00:11:03,700 --> 00:11:08,530 Now we're going to find out why that is and that's because our switch must be exhaustive. 162 00:11:08,650 --> 00:11:13,890 A barcode can be UPC or QR code so we need to give it an option to do something. 163 00:11:13,900 --> 00:11:19,630 If a QR code gets passed in otherwise the app could crash so it's helping us to be safe actually which 164 00:11:19,630 --> 00:11:20,640 is pretty cool. 165 00:11:20,980 --> 00:11:27,130 Also at the end of a case for a switch we need to put a colon so it knows that that's the end of that 166 00:11:27,130 --> 00:11:27,880 case. 167 00:11:27,990 --> 00:11:31,930 OK let's go ahead and let's do that now for a QR code. 168 00:11:31,960 --> 00:11:38,910 So case let QR code and what we're going to do is we simply just have a product code. 169 00:11:39,170 --> 00:11:39,600 OK. 170 00:11:39,640 --> 00:11:44,870 Because for a QR code we're only passing in one value which is a string. 171 00:11:44,870 --> 00:11:53,320 So for the case product code we're going to go ahead and just print QR code and we're going to just 172 00:11:53,320 --> 00:11:56,570 give it the product like so. 173 00:11:56,980 --> 00:11:57,560 All right. 174 00:11:57,730 --> 00:12:00,250 So now our switch is exhaustive. 175 00:12:00,340 --> 00:12:05,010 It's giving us an error though let's figure out what the problem is. 176 00:12:05,080 --> 00:12:10,130 We have said case let UPC number system manufacturer product code check. 177 00:12:10,300 --> 00:12:10,770 Oh OK. 178 00:12:10,780 --> 00:12:14,540 So the colon is in the wrong place my bet I put it at the end of the print statement. 179 00:12:14,710 --> 00:12:15,050 Cool. 180 00:12:15,070 --> 00:12:15,820 There we go. 181 00:12:15,820 --> 00:12:17,390 That looks wonderful. 182 00:12:17,430 --> 00:12:24,850 So do some cleanup here and now you can see it prints because it is a UPC barcode printed out 8 4 8 183 00:12:24,850 --> 00:12:27,100 5 9 9 5 1 2 2 6 and 3. 184 00:12:27,100 --> 00:12:29,910 So now we have access to those values. 185 00:12:30,040 --> 00:12:30,860 Really cool. 186 00:12:31,000 --> 00:12:36,470 But what happens if I wanted to change the product barcode into a QR code. 187 00:12:36,760 --> 00:12:44,470 We could do that by just setting product barcode equals dot QR code and we can give it a string value. 188 00:12:44,470 --> 00:12:48,730 So for that I'll just type a bunch of random characters and now that it's a QR code watch what happens 189 00:12:48,730 --> 00:12:50,320 when it goes through the switch statement. 190 00:12:50,560 --> 00:12:52,550 It prints it out as a QR code. 191 00:12:52,570 --> 00:12:53,290 That's really cool. 192 00:12:53,290 --> 00:12:59,080 So as you can see enumerations are really helpful and they can be used for a lot of different things 193 00:12:59,800 --> 00:13:01,630 beyond associated values. 194 00:13:01,630 --> 00:13:07,050 We can do lots of different things like we can set explicit values and types for our enumerations. 195 00:13:07,050 --> 00:13:07,990 So I'm gonna show you that. 196 00:13:07,990 --> 00:13:13,480 Now let me pull this back open in full screen here and let's give us some space so we can actually see 197 00:13:14,140 --> 00:13:15,460 where we go. 198 00:13:15,760 --> 00:13:24,290 So I'm going to create a numeration for Jet II masters and let's do that by typing ENM jet I. 199 00:13:24,350 --> 00:13:30,370 M. Of course we're using the kind of conventions that you would for declaring a class with capital letters 200 00:13:30,370 --> 00:13:31,340 at the beginning. 201 00:13:31,450 --> 00:13:36,040 And what we're going to do is we're going to set up a few different cases so some jet masters that I 202 00:13:36,040 --> 00:13:43,530 can remember right now are let's do case yota case Mace Windu. 203 00:13:43,870 --> 00:13:47,760 How about Kwai Gunjan. 204 00:13:47,950 --> 00:13:50,240 To end their case. 205 00:13:50,290 --> 00:13:52,840 Obi Wan Kenobi. 206 00:13:52,870 --> 00:13:53,730 Who else. 207 00:13:53,790 --> 00:13:56,260 I'm Luke Skywalker. 208 00:13:56,290 --> 00:13:58,500 I guess he could be in there. 209 00:13:58,570 --> 00:14:06,280 So as you can see there are a bunch of different Jedi Masters in our enumeration and if we were to print 210 00:14:06,280 --> 00:14:12,670 this out watch what happens if we print Jedi Master dot Yoda. 211 00:14:12,700 --> 00:14:15,660 Watch what Prince out. 212 00:14:15,690 --> 00:14:19,080 So you can see Yoda with a lowercase why Prince out. 213 00:14:19,320 --> 00:14:23,320 And that's because since this is just text we haven't really told anything else. 214 00:14:23,400 --> 00:14:28,530 It's actually inferring that it is a string which is cool it lets us print it out and that's really 215 00:14:28,530 --> 00:14:29,400 helpful. 216 00:14:29,400 --> 00:14:33,160 But what if I wanted to include Yoda's name in an app. 217 00:14:33,180 --> 00:14:37,090 Of course since it's a proper noun it should have a capital letter at the beginning. 218 00:14:37,200 --> 00:14:40,470 I can do that by setting an explicit type for this enumeration. 219 00:14:40,530 --> 00:14:47,040 So to do that you can actually do it just like you would inherit in a class by typing a colon and adding 220 00:14:47,040 --> 00:14:47,920 string. 221 00:14:48,270 --> 00:14:51,980 So now each of these cases are explicitly a string. 222 00:14:51,990 --> 00:14:57,660 But what we can do is we can set a value for these cases and we can access it by pulling out the raw 223 00:14:57,660 --> 00:14:58,420 value. 224 00:14:58,440 --> 00:15:06,330 So just like you would with a constant or variable go Hedden type Yoda K with a capital letter. 225 00:15:06,780 --> 00:15:10,490 Go ahead and type Mace Windu. 226 00:15:10,780 --> 00:15:13,350 Go ahead and try whoopsies. 227 00:15:13,500 --> 00:15:14,140 Come on. 228 00:15:14,370 --> 00:15:21,340 Go ahead and type q a gun gin. 229 00:15:21,840 --> 00:15:23,180 Go ahead Hi. 230 00:15:23,220 --> 00:15:26,190 Obi Wan Kenobi. 231 00:15:26,910 --> 00:15:32,720 And go ahead and type Luke Skywalker without the capital K. 232 00:15:33,060 --> 00:15:33,690 OK cool. 233 00:15:33,690 --> 00:15:39,420 So as you can see these all now have an explicit string type which is really cool but you probably notice 234 00:15:39,420 --> 00:15:44,970 that Yoda is still printing out lowercase which is the value for the case but not the explicit value 235 00:15:44,970 --> 00:15:49,890 we've set to access that all we need to do is pull out the raw value. 236 00:15:49,890 --> 00:15:50,490 Watch what happens. 237 00:15:50,490 --> 00:15:53,430 Now when I print it prints out the capital Y Yoda. 238 00:15:53,430 --> 00:16:01,200 If I were to change that to master yoda you can see it prints out Master Yoda the explicit string value 239 00:16:01,200 --> 00:16:03,230 that we've set which is super cool. 240 00:16:03,420 --> 00:16:05,550 So you can do this for all kinds of things. 241 00:16:05,550 --> 00:16:10,860 Integers doubles even your own custom types or classes which is really neat. 242 00:16:10,980 --> 00:16:16,980 And so we just printed out the raw value for the explicit type that we've set for this enumeration. 243 00:16:16,980 --> 00:16:17,620 But you know what. 244 00:16:17,630 --> 00:16:19,840 This is not really super practical. 245 00:16:19,850 --> 00:16:22,320 And these are all just sort of toy examples. 246 00:16:22,320 --> 00:16:28,470 I want to show you now how you could manage the state of a switch or a button by basically just creating 247 00:16:28,470 --> 00:16:33,380 a simple enumeration to hold the status of a switch on or off. 248 00:16:33,390 --> 00:16:36,420 It's simple but it's something that you could do in an app. 249 00:16:36,420 --> 00:16:40,720 So go ahead and type Inam switch status. 250 00:16:41,050 --> 00:16:47,390 OK and we're going to set two cases on and off which makes sense so go ahead and type case on. 251 00:16:47,730 --> 00:16:54,060 And case off there's two options right now what we're going to do is we're going to go ahead and create 252 00:16:54,060 --> 00:17:00,120 a variable that's going to hold the value for our or switch status and we're going to set it to be equal 253 00:17:00,120 --> 00:17:04,140 to off initially and then toggle it using a function. 254 00:17:04,140 --> 00:17:05,390 So let's do that now. 255 00:17:05,600 --> 00:17:08,500 Go ahead and type var switch status. 256 00:17:08,910 --> 00:17:12,860 Let's make it explicitly of type switch. 257 00:17:12,930 --> 00:17:15,400 Oh my gosh let's make it explode. 258 00:17:15,720 --> 00:17:20,660 Explicitly switch status and let's set it to be dot. 259 00:17:21,030 --> 00:17:23,780 And as you can see we have our two options here that pop up. 260 00:17:23,820 --> 00:17:27,140 We'll set it to be off from the beginning already. 261 00:17:27,280 --> 00:17:33,930 Now we're going to write a function that is going to invert the value of our switch status if if it's 262 00:17:34,020 --> 00:17:36,990 off we'll run through the function and it'll return on. 263 00:17:37,200 --> 00:17:39,420 If it's on we're going to return off. 264 00:17:39,420 --> 00:17:40,100 Super simple. 265 00:17:40,110 --> 00:17:41,840 So go ahead and write phunk. 266 00:17:42,160 --> 00:17:44,370 Whoops flip switch. 267 00:17:44,850 --> 00:17:45,510 OK. 268 00:17:45,510 --> 00:17:52,340 We're going to pass in a status of type switch status and we're going to return a switch status as well. 269 00:17:52,650 --> 00:18:03,860 OK so if we pass in a status of off if status is equal to off we're going to go ahead and return on. 270 00:18:03,930 --> 00:18:04,170 Right. 271 00:18:04,170 --> 00:18:09,870 That makes sense if it's off we're going to turn it on else meaning if we pass it on we're going to 272 00:18:09,870 --> 00:18:15,250 return off just like that get really cool super simple. 273 00:18:15,540 --> 00:18:20,160 So we have returned on or off depending on what status we get passed in. 274 00:18:20,160 --> 00:18:25,980 Now let's go ahead remember that our switch status is currently off and what we're going to do is we're 275 00:18:25,980 --> 00:18:30,960 going to go ahead and call flip switch which is our function and we're going to show how the status 276 00:18:30,960 --> 00:18:32,990 of our switch is going to be flipped. 277 00:18:33,030 --> 00:18:38,710 Remember it's off now and if I pass in switch status whips the one with the lowercase S.. 278 00:18:38,790 --> 00:18:42,400 Watch what happens when it prints out in the function over here. 279 00:18:42,420 --> 00:18:43,300 Now it's on. 280 00:18:43,400 --> 00:18:43,600 OK. 281 00:18:43,600 --> 00:18:44,790 Really cool. 282 00:18:45,150 --> 00:18:52,680 If I wanted to set our switch status to be equal to on and then if I pass it into our function now watch 283 00:18:52,680 --> 00:18:53,480 what happens. 284 00:18:53,670 --> 00:18:56,960 Let's pass in switch status and it's on remember. 285 00:18:57,060 --> 00:19:01,190 I set it on watch what happens when I flip it it sets it to off. 286 00:19:01,200 --> 00:19:08,250 So we're using an enumeration to handle on these related values and we can use enumerations to do all 287 00:19:08,250 --> 00:19:09,430 kinds of cool things. 288 00:19:09,450 --> 00:19:11,120 You can set associated values. 289 00:19:11,130 --> 00:19:15,100 You can set explicit types and raw values for those explicit types. 290 00:19:15,240 --> 00:19:21,150 You can use tuples and pass in those values to your associated types. 291 00:19:21,150 --> 00:19:26,100 You can do all kinds of really really cool stuff and there's much more if you dig into the Apple documentation 292 00:19:26,400 --> 00:19:28,080 on enumerations you can learn much more. 293 00:19:28,080 --> 00:19:32,320 But this is just kind of to cover the basics of enumerations and all they can do to help you. 294 00:19:32,340 --> 00:19:34,800 So let's go ahead and let's move over to the next video. 295 00:19:34,800 --> 00:19:36,470 This is Calleigh with Debb slopes. 296 00:19:36,490 --> 00:19:36,850 Scott.