1 00:00:08,130 --> 00:00:10,800 Hey buddy this is Caleb with Devon Lopes dot com. 2 00:00:10,830 --> 00:00:14,550 And in this video we're going to be talking about enumerations. 3 00:00:14,550 --> 00:00:18,170 Enumerations are a really cool thing and swift. 4 00:00:18,180 --> 00:00:24,030 It's a type that basically contains a group of related values that are all kind of under the same on 5 00:00:24,030 --> 00:00:25,910 Barela as each other. 6 00:00:25,920 --> 00:00:31,170 So if you think about like a you know car is the big umbrella you might have Maserati Lamborghini Geo 7 00:00:31,170 --> 00:00:32,150 Metro. 8 00:00:32,280 --> 00:00:33,430 Nice. 9 00:00:33,540 --> 00:00:36,690 If you think about fruit you might have banana apple orange. 10 00:00:36,690 --> 00:00:43,220 They're all related values under the same overarching type which is you know a cool way to manage it. 11 00:00:43,500 --> 00:00:50,070 And basically what an enumeration allows us to do is we can work with those values in a type safe way 12 00:00:50,520 --> 00:00:51,560 which is really neat. 13 00:00:51,720 --> 00:00:56,730 So to show you how this works I'm actually going to go ahead and create a playground and we're going 14 00:00:56,730 --> 00:01:00,520 to go ahead and I'm going to teach you the syntax of an enumeration. 15 00:01:00,900 --> 00:01:04,710 I'm going to show you a couple of different things you can do with enumerations and then at the very 16 00:01:04,710 --> 00:01:10,260 end I'm going to show you a practical example that you could actually use in an application so you know 17 00:01:10,260 --> 00:01:11,430 how you can use this. 18 00:01:11,430 --> 00:01:15,930 So let's go ahead and click get started with the playground and it should pop up. 19 00:01:15,930 --> 00:01:17,530 Popped up on my other window here. 20 00:01:17,640 --> 00:01:22,230 But for now let's create a blank playground and I'm just going to name it. 21 00:01:22,440 --> 00:01:28,920 You know as a teacher I'm the teacher you can name it whatever you want and go ahead and bump that open 22 00:01:28,920 --> 00:01:30,340 into fullscreen. 23 00:01:30,870 --> 00:01:32,600 And we're going to go ahead. 24 00:01:32,850 --> 00:01:34,640 You know what this might be an X code beta bug. 25 00:01:34,650 --> 00:01:38,650 It looks like we're not going to be able to stretch that any wider but that's fine. 26 00:01:38,910 --> 00:01:44,160 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 00:01:44,760 --> 00:01:46,180 and let's begin. 28 00:01:46,500 --> 00:01:52,420 So the syntax of an enumeration goes like this you declare it by typing inam. 29 00:01:52,500 --> 00:01:54,640 OK that's short for enumeration. 30 00:01:54,900 --> 00:02:00,190 And then you give it a name and think of these names like you would name a class. 31 00:02:00,200 --> 00:02:04,510 OK so you're going to use capital letters at the very beginning for every word. 32 00:02:04,530 --> 00:02:05,840 It will have a capital. 33 00:02:05,840 --> 00:02:10,390 So just for example name of them. 34 00:02:10,710 --> 00:02:14,090 And then you're going to give it some curly braces just like a class. 35 00:02:14,130 --> 00:02:19,910 Now inside an enumeration we're going to go ahead and we're going to set up cases. 36 00:02:19,920 --> 00:02:20,520 OK. 37 00:02:20,760 --> 00:02:26,670 If you've ever used a switch statement you're familiar with these a switch basically allows you to go 38 00:02:26,670 --> 00:02:31,700 through a bunch of different options and you call each one of those options a case. 39 00:02:31,800 --> 00:02:38,010 And so for an enumeration we're going to give it cases as well so I'm just going to say case case one 40 00:02:38,640 --> 00:02:43,140 case case to case case three. 41 00:02:43,210 --> 00:02:43,660 OK. 42 00:02:43,680 --> 00:02:47,300 Now of course these would be named something differently in a different enumeration. 43 00:02:47,310 --> 00:02:49,180 But for now this is just an example. 44 00:02:49,260 --> 00:02:53,680 And as you can see the enumeration has three separate cases. 45 00:02:53,850 --> 00:03:02,700 And in order to instantiate that all you need to do is to set up let in numeration and we can make it 46 00:03:02,730 --> 00:03:03,760 of type. 47 00:03:04,110 --> 00:03:08,250 Well actually let's do a call in there make it of type name of a name. 48 00:03:08,280 --> 00:03:12,570 This of course is a terrible name but it's just for an example I'll show you some real examples in a 49 00:03:12,570 --> 00:03:13,310 second. 50 00:03:13,590 --> 00:03:16,760 And we can set that to be equal to one of our cases. 51 00:03:16,830 --> 00:03:20,000 Ok I'll show you why this is useful in just a little bit. 52 00:03:20,160 --> 00:03:22,750 Now to actually access these cases I can't just type. 53 00:03:22,750 --> 00:03:25,070 Case one you'll see it doesn't pop up. 54 00:03:25,320 --> 00:03:31,680 But what I can do is I can type a period and that will give me access to all three of the different 55 00:03:31,680 --> 00:03:32,640 cases that I've set. 56 00:03:32,640 --> 00:03:35,300 So let's set this to be equal to case two. 57 00:03:35,550 --> 00:03:39,420 And now you can see its value on the screen there is set to be case to. 58 00:03:39,800 --> 00:03:40,870 That's pretty cool. 59 00:03:41,190 --> 00:03:48,000 So this is the basic syntax of an enumeration you declare with ENM and you give it cases OK. 60 00:03:48,210 --> 00:03:56,010 Like I said before Karr could be the name of the enim and the cases could be DeLorean Maserati Lamborghini 61 00:03:56,220 --> 00:03:58,180 Cato's could be all the different cases. 62 00:03:58,260 --> 00:04:01,680 Now you don't have to declare each case on a separate line. 63 00:04:01,800 --> 00:04:04,470 You can actually just go ahead and use commas. 64 00:04:04,530 --> 00:04:04,760 OK. 65 00:04:04,770 --> 00:04:10,410 Just like when you create multiple constants or variables you can declare them in one straight line 66 00:04:10,410 --> 00:04:11,450 by using commas. 67 00:04:11,490 --> 00:04:17,060 So just type case one comma case two comma case three. 68 00:04:17,310 --> 00:04:19,960 And as you can see that works just the same. 69 00:04:20,100 --> 00:04:21,570 Ok pretty cool. 70 00:04:21,570 --> 00:04:23,940 So let's go ahead and let's move on. 71 00:04:23,940 --> 00:04:25,610 I'm going to show you some other cool things. 72 00:04:25,630 --> 00:04:27,210 Enumerations can do. 73 00:04:27,510 --> 00:04:31,610 And one of those things actually is a really great example from Apple. 74 00:04:31,740 --> 00:04:37,440 So I'm going to pull open these two bar codes here and barcodes are a great example because enumerations 75 00:04:37,440 --> 00:04:44,910 allow us to work with related values but they also are good for kind of differentiating different types 76 00:04:44,940 --> 00:04:45,870 of things. 77 00:04:45,930 --> 00:04:53,340 And so here we have a standard UPC product bar code and we also have a QR code which is used for you 78 00:04:53,340 --> 00:04:56,670 know all kinds of different things storing all kinds of different information. 79 00:04:56,670 --> 00:05:01,890 So there are very different kinds of barcodes but they are both barcodes. 80 00:05:01,890 --> 00:05:07,420 So we're going to create an enumeration for barcode but we're going to give it to cases one will be 81 00:05:07,480 --> 00:05:13,300 UPC 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 00:05:13,300 --> 00:05:15,310 create one for the QR code. 83 00:05:15,310 --> 00:05:21,310 So go ahead and type ENM barcode and we're going to give it two cases. 84 00:05:21,370 --> 00:05:24,720 The first case will be case UPC. 85 00:05:24,790 --> 00:05:31,760 The second will be case wups case and Q are code just like that. 86 00:05:31,810 --> 00:05:38,090 Now we're going to be able to put in associated values into this barcode enumeration. 87 00:05:38,230 --> 00:05:43,300 And what that's going to allow us to do is whenever we create an instance of barcode. 88 00:05:43,450 --> 00:05:49,540 And let's just say that we create an instance of barcode UPC will be able to pass in values that are 89 00:05:49,540 --> 00:05:53,130 associated with that and then use those later or modify them. 90 00:05:53,130 --> 00:05:54,110 It's really cool. 91 00:05:54,310 --> 00:06:00,160 So for a UPC for a product barcode you'll notice there are four different numbers. 92 00:06:00,160 --> 00:06:07,180 Now at the beginning there is a number that denotes the specific number system k that a certain product 93 00:06:07,360 --> 00:06:08,860 might use. 94 00:06:09,190 --> 00:06:15,480 The second set of numbers is to denote the manufacturer who makes the product. 95 00:06:15,490 --> 00:06:19,680 Third is the product name or the product value. 96 00:06:19,690 --> 00:06:24,850 Basically these numbers are associated with a specific product and then at the very end there's what's 97 00:06:24,850 --> 00:06:31,390 called a check and that basically allows for the store to know whether or not the barcode was scanned 98 00:06:31,450 --> 00:06:32,270 successfully. 99 00:06:32,280 --> 00:06:32,790 OK. 100 00:06:33,070 --> 00:06:34,530 So there are four values. 101 00:06:34,600 --> 00:06:39,760 And what we're going to do is we're actually going to just put a parentheses next to you PC and we can 102 00:06:39,760 --> 00:06:47,830 pass in four separate values in a couple which a couple is as you know a list of values unrelated or 103 00:06:47,830 --> 00:06:48,350 related. 104 00:06:48,360 --> 00:06:48,610 OK. 105 00:06:48,640 --> 00:06:49,940 That can be either. 106 00:06:50,050 --> 00:06:54,520 Now the values in this table are going to be related and it's actually going to just be for integers 107 00:06:55,050 --> 00:06:57,940 one for each of the separate number values and our barcode. 108 00:06:57,940 --> 00:07:03,910 So go ahead and just type int comma int and do that four times like so. 109 00:07:03,910 --> 00:07:05,280 And for the QR code. 110 00:07:05,350 --> 00:07:10,930 The cool thing is a QR code can hold all kinds of information and data actually up to like two thousand 111 00:07:10,930 --> 00:07:13,280 nine hundred fifty characters or something. 112 00:07:13,600 --> 00:07:18,040 But what we're going to do is instead of passing multiple values we're just going to pass in one string 113 00:07:18,040 --> 00:07:25,240 value because oftentimes QR codes hold textual data K like a U R L or account information. 114 00:07:25,590 --> 00:07:25,870 OK. 115 00:07:25,870 --> 00:07:26,700 Very cool. 116 00:07:26,710 --> 00:07:32,650 So now that we have these associated values with our enumeration what we're going to be able to do is 117 00:07:32,650 --> 00:07:36,740 create an instance of it and pass in those values and then we can use them later on. 118 00:07:36,760 --> 00:07:43,390 So let's go ahead and let's create a barcode by typing var product barcode and we're going to set that 119 00:07:43,390 --> 00:07:44,980 to be equal to Barka. 120 00:07:45,490 --> 00:07:51,480 And if we push the little if we give a period there we can choose UPC or QR code. 121 00:07:51,580 --> 00:07:53,660 OK let's choose a UPC for now. 122 00:07:53,920 --> 00:07:58,900 And as you can see it looks a little bit like a function we're passing in values and we're basically 123 00:07:58,900 --> 00:08:04,250 just setting them as for little temporary variables inside of this barcode. 124 00:08:04,240 --> 00:08:08,420 So let's go ahead and let's give the values from our UPC here. 125 00:08:08,470 --> 00:08:15,040 So the manufacturer is or sorry the what's it called the number system is what the manufacturer is 8 126 00:08:15,100 --> 00:08:21,770 5 9 0 9 the product number is 5 1 2 2 6 and the check number is 3. 127 00:08:21,940 --> 00:08:25,510 So that's cool and all but what if I wanted to print this out if I type. 128 00:08:25,510 --> 00:08:27,600 Print product barcode. 129 00:08:27,640 --> 00:08:28,570 Watch what happens. 130 00:08:28,600 --> 00:08:31,470 It will print down here at the bottom in just a moment. 131 00:08:33,550 --> 00:08:37,380 So as you can see it prints out UPC and it prints out our four values. 132 00:08:37,390 --> 00:08:41,920 That's pretty cool but we can't exactly access them or pull them out in any way as you see. 133 00:08:41,920 --> 00:08:44,640 Nothing pops up when I type a period at the end of that. 134 00:08:44,800 --> 00:08:47,590 So we can't actually access it that way. 135 00:08:47,830 --> 00:08:49,910 But check out what we can do. 136 00:08:50,020 --> 00:08:55,990 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 137 00:08:55,990 --> 00:09:01,660 to create a temporary constant and we're going to assign four constant values to the four values in 138 00:09:01,660 --> 00:09:04,570 our UPC then we can work with them and modify them. 139 00:09:04,570 --> 00:09:09,170 So let's go ahead and let's create a switch statement for product barcode. 140 00:09:09,610 --> 00:09:10,110 OK. 141 00:09:10,120 --> 00:09:13,600 And we're going to give it to cases UPC or QR code. 142 00:09:13,840 --> 00:09:19,580 So go ahead and type case and the only thing by the way since it is of type barcode The only things 143 00:09:19,580 --> 00:09:23,590 that can be are a UPC or a QR code. 144 00:09:23,650 --> 00:09:29,200 So we're going to go ahead and create some constants here so inciter switch statement here we're going 145 00:09:29,200 --> 00:09:33,950 to go ahead and create four constants by typing let dot UPC. 146 00:09:34,150 --> 00:09:40,180 So we're basically saying for a PC we're going to set four constants for these four values and to do 147 00:09:40,180 --> 00:09:46,850 that go ahead and type parentheses and just like I said we're going to type number system. 148 00:09:47,050 --> 00:09:48,520 That's the first number. 149 00:09:48,520 --> 00:09:55,770 Then the manufacturer then the product then the end is a check. 150 00:09:55,950 --> 00:09:56,470 OK. 151 00:09:56,770 --> 00:10:02,920 Now we're using Let here and just like we did up here with the three cases on the same line by typing 152 00:10:02,920 --> 00:10:08,060 let here and number system manufacturer product check we're creating four separate constants. 153 00:10:08,230 --> 00:10:12,290 And what we're going to do is once we have those four values set we can print them out. 154 00:10:12,310 --> 00:10:22,380 So print and whoops we're going to go ahead and print UPC and then using string interpolation we're 155 00:10:22,430 --> 00:10:29,170 gonna go ahead and pass these four constants we've created in and see if the values get properly passed. 156 00:10:29,170 --> 00:10:35,140 So inside of our special string interpellation syntax go ahead and type number system and then you know 157 00:10:35,140 --> 00:10:35,280 what. 158 00:10:35,290 --> 00:10:40,930 Let's actually before we type that let's copy and paste this so we don't have to type it so many times. 159 00:10:40,930 --> 00:10:41,390 There we go. 160 00:10:41,410 --> 00:10:43,300 So let's print number system. 161 00:10:43,690 --> 00:10:52,570 OK then let's print manufacturer then product Whoops you know what let's call that product code. 162 00:10:52,570 --> 00:10:56,270 Actually I like that better product code. 163 00:10:56,320 --> 00:10:58,500 And at the end we're going to print the check value. 164 00:10:58,570 --> 00:11:03,760 So watch what happens when this runs through it says that it has failed. 165 00:11:03,760 --> 00:11:08,710 Now we're going to find out why that is and that's because our switch must be exhaustive. 166 00:11:08,710 --> 00:11:13,950 A barcode can be UPC or QR code so we need to give it an option to do something. 167 00:11:13,960 --> 00:11:19,690 If a QR code gets passed in otherwise the app could crash so it's helping us to be safe actually which 168 00:11:19,690 --> 00:11:21,040 is pretty cool. 169 00:11:21,040 --> 00:11:27,190 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 170 00:11:27,190 --> 00:11:27,940 case. 171 00:11:28,050 --> 00:11:32,000 OK let's go ahead and let's do that now for a QR code. 172 00:11:32,030 --> 00:11:38,980 So case let QR code and what we're going to do is we simply just have a product code. 173 00:11:39,280 --> 00:11:39,650 OK. 174 00:11:39,700 --> 00:11:44,590 Because for a QR code we're only passing in one value which is a string. 175 00:11:44,920 --> 00:11:53,380 So for the case product code we're going to go ahead and just print QR code and we're going to just 176 00:11:53,380 --> 00:11:56,630 give it the product like so. 177 00:11:57,040 --> 00:11:57,620 All right. 178 00:11:57,790 --> 00:12:00,300 So now our switch is exhaustive. 179 00:12:00,400 --> 00:12:05,050 It's giving us an error though let's figure out what the problem is. 180 00:12:05,110 --> 00:12:10,190 We have said case L'Etat UPC number system manufacturer product code check. 181 00:12:10,360 --> 00:12:10,830 Oh OK. 182 00:12:10,840 --> 00:12:12,650 So the colon is in the wrong place my bet. 183 00:12:12,670 --> 00:12:14,670 I put it at the end of the print statement. 184 00:12:14,730 --> 00:12:15,120 Cool. 185 00:12:15,130 --> 00:12:15,880 There we go. 186 00:12:15,880 --> 00:12:17,450 That looks wonderful. 187 00:12:17,500 --> 00:12:24,880 So do some cleanup here and now you can see it prints because it is a UPC barcode printed out 8 4 8 188 00:12:24,880 --> 00:12:27,160 5 9 9 5 1 2 2 6 and 3. 189 00:12:27,160 --> 00:12:29,980 So now we have access to those values. 190 00:12:30,100 --> 00:12:30,810 Really cool. 191 00:12:31,060 --> 00:12:36,690 But what happens if I wanted to change the product barcode into a QR code. 192 00:12:36,820 --> 00:12:44,480 We could do that by just setting product barcode equals dot QR code and we can give it a string value. 193 00:12:44,500 --> 00:12:48,790 So for that I'll just type a bunch of random characters and now that it's a QR code watch what happens 194 00:12:48,790 --> 00:12:50,360 when it goes through the switch statement. 195 00:12:50,590 --> 00:12:52,610 It prints it out as a QR code. 196 00:12:52,630 --> 00:12:53,350 That's really cool. 197 00:12:53,350 --> 00:12:59,140 So as you can see enumerations are really helpful and they can be used for a lot of different things 198 00:12:59,860 --> 00:13:01,690 beyond dissociated values. 199 00:13:01,690 --> 00:13:07,110 We can do lots of different things like we can set explicit values and types for our enumerations. 200 00:13:07,120 --> 00:13:08,490 So I'm gonna show you that now. 201 00:13:08,680 --> 00:13:14,100 Let me pull this back open in full screen here and let's give us some space so we can actually see. 202 00:13:14,660 --> 00:13:15,530 There we go. 203 00:13:15,820 --> 00:13:24,270 So I'm going to create a numeration for Jet II masters and let's do that by typing ENM jet. 204 00:13:24,360 --> 00:13:30,430 M. Of course we're using the kind of conventions that you would for declaring a class with capital letters 205 00:13:30,430 --> 00:13:31,340 at the beginning. 206 00:13:31,510 --> 00:13:36,100 And what we're going to do is we're going to set up a few different cases so some jet masters that I 207 00:13:36,100 --> 00:13:43,440 can remember right now are let's do case yota case Mace Windu. 208 00:13:43,930 --> 00:13:50,300 How about Kwai Gunjan upstairs to end their case. 209 00:13:50,350 --> 00:13:52,900 Obi Wan Kenobi. 210 00:13:52,930 --> 00:13:53,780 Who else. 211 00:13:53,830 --> 00:13:56,320 I'm Luke Skywalker. 212 00:13:56,350 --> 00:13:58,560 I guess he could be in there. 213 00:13:58,630 --> 00:14:06,310 So as you can see there are a bunch of different masters in our enumeration and if we were to print 214 00:14:06,340 --> 00:14:12,720 this out watch what happens if we print master datt Yoda. 215 00:14:12,760 --> 00:14:15,690 Watch what Prince out. 216 00:14:15,750 --> 00:14:19,210 So you can see Yoda with a lowercase why prints out. 217 00:14:19,380 --> 00:14:23,390 And that's because since this is just text we haven't really told anything else. 218 00:14:23,460 --> 00:14:28,590 It's actually inferring that it is a string which is cool it lets us print it out and that's really 219 00:14:28,590 --> 00:14:29,340 helpful. 220 00:14:29,460 --> 00:14:33,200 But what if I wanted to include Yoda's name in an app. 221 00:14:33,210 --> 00:14:37,150 Of course since it's a proper noun it should have a capital letter at the beginning. 222 00:14:37,260 --> 00:14:40,440 I can do that by setting an explicit type for this enumeration. 223 00:14:40,590 --> 00:14:47,100 So to do that you can actually do it just like you would inherit in a class by typing a colon and adding 224 00:14:47,100 --> 00:14:47,980 string. 225 00:14:48,330 --> 00:14:52,050 So now each of these cases are explicitly a string. 226 00:14:52,050 --> 00:14:57,720 But what we can do is we can set a value for these cases and we can access it by pulling out the raw 227 00:14:57,720 --> 00:14:58,480 value. 228 00:14:58,500 --> 00:15:06,960 So just like you would with a constant or variable go ahead and type Yoda K with a capital letter go 229 00:15:06,960 --> 00:15:10,570 ahead and type Mace Windu. 230 00:15:10,880 --> 00:15:13,560 Go ahead and try whoopsies. 231 00:15:13,560 --> 00:15:14,210 Come on. 232 00:15:14,430 --> 00:15:20,130 Go ahead and type q a gun. 233 00:15:20,180 --> 00:15:22,000 Gin. 234 00:15:22,130 --> 00:15:22,620 Go ahead. 235 00:15:22,630 --> 00:15:23,230 Hi. 236 00:15:23,280 --> 00:15:26,290 Obi Wan Kenobi. 237 00:15:26,970 --> 00:15:32,770 And go ahead and type Luke Skywalker without the capital K. 238 00:15:33,120 --> 00:15:33,720 Ok cool. 239 00:15:33,720 --> 00:15:39,480 So as you can see these all now have an explicit string type which is really cool but you probably noticed 240 00:15:39,480 --> 00:15:45,030 that Yoda is still printing out lowercase which is the value for the case but not the explicit value 241 00:15:45,030 --> 00:15:49,930 we've set to access that all we need to do is pull out the raw value. 242 00:15:49,950 --> 00:15:50,550 Watch what happens. 243 00:15:50,550 --> 00:15:53,490 Now when I print it prints out the capital Y Yoda. 244 00:15:53,490 --> 00:16:01,260 If I were to change that to master yoda you can see it prints out Master Yoda the explicit string value 245 00:16:01,260 --> 00:16:03,480 that we've set which is super cool. 246 00:16:03,480 --> 00:16:05,610 So you can do this for all kinds of things. 247 00:16:05,610 --> 00:16:10,910 Integers doubles even your own custom types or classes which is really neat. 248 00:16:11,040 --> 00:16:16,840 And so we just printed out the raw value for the explicit type that we've set for this enumeration. 249 00:16:17,070 --> 00:16:19,880 But you know what this is not really super practical. 250 00:16:19,900 --> 00:16:22,350 And these are all just sort of toy examples. 251 00:16:22,380 --> 00:16:28,530 I want to show you now how you could manage the state of a switch or a button by basically just creating 252 00:16:28,530 --> 00:16:33,440 a simple enumeration to hold the status of a switch on or off. 253 00:16:33,450 --> 00:16:36,210 It's simple but it's something that you could do in an app. 254 00:16:36,480 --> 00:16:40,900 So go ahead and type in them switch status. 255 00:16:41,130 --> 00:16:48,330 OK and we're going to set two cases on and off which makes sense so go ahead and type case on IN CASE 256 00:16:48,600 --> 00:16:49,920 off. 257 00:16:49,920 --> 00:16:54,930 There's two options right now what we're going to do is we're going to go ahead and create a variable 258 00:16:55,080 --> 00:17:01,740 that's going to hold the value for our or switch status and we're going to set it to be equal to off 259 00:17:01,770 --> 00:17:04,200 initially and then toggle it using a function. 260 00:17:04,200 --> 00:17:05,480 So let's do that now. 261 00:17:05,670 --> 00:17:08,550 Go ahead and type var switch status. 262 00:17:08,970 --> 00:17:12,920 Let's make it explicitly of type switch. 263 00:17:12,990 --> 00:17:15,480 Oh my gosh let's make it explode. 264 00:17:15,780 --> 00:17:20,720 Explicitly switch status and let's set it to be dot. 265 00:17:21,090 --> 00:17:23,860 And as you can see we have our two options here that pop up. 266 00:17:23,880 --> 00:17:27,250 We'll set it to be off from the beginning already. 267 00:17:27,350 --> 00:17:33,990 Now we're going to write a function that is going to invert the value of our switch status if if it's 268 00:17:34,080 --> 00:17:37,950 off we'll run it to the function and it will return on if it's on. 269 00:17:37,960 --> 00:17:40,160 We're going to return off super simple. 270 00:17:40,170 --> 00:17:41,880 So go ahead and write func. 271 00:17:42,210 --> 00:17:44,430 Whoops flip switch. 272 00:17:44,910 --> 00:17:45,530 OK. 273 00:17:45,570 --> 00:17:52,380 We're going to pass in a status of type switch status and we're going to return a switch status as well. 274 00:17:52,710 --> 00:17:53,350 OK. 275 00:17:53,550 --> 00:18:03,920 So if we pass in a status of off if status is equal to off we're going to go ahead and return on. 276 00:18:03,990 --> 00:18:04,230 Right. 277 00:18:04,230 --> 00:18:09,930 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 278 00:18:09,940 --> 00:18:13,040 return off just like that. 279 00:18:13,430 --> 00:18:13,710 OK. 280 00:18:13,740 --> 00:18:14,400 Really cool. 281 00:18:14,400 --> 00:18:15,520 Super simple. 282 00:18:15,600 --> 00:18:20,220 So we have turned on or off depending on what status we get passed in. 283 00:18:20,220 --> 00:18:26,010 Now let's go ahead remember that our switch status is currently off and what we're going to do is we're 284 00:18:26,010 --> 00:18:31,020 going to go ahead and call flip switch which is our function and we're going to show how the status 285 00:18:31,020 --> 00:18:33,080 of our switch is going to be flipped. 286 00:18:33,090 --> 00:18:34,510 Remember it's off now. 287 00:18:34,650 --> 00:18:38,820 And if I pass in switch status whips the one with the lower case s. 288 00:18:38,850 --> 00:18:42,480 Watch what happens when it prints out in the function over here. 289 00:18:42,480 --> 00:18:44,800 Now it's on really cool. 290 00:18:45,210 --> 00:18:52,740 If I wanted to set our switch status to be equal to on and then if I pass it into our function now watch 291 00:18:52,740 --> 00:18:59,100 what happens let's pass in switch status and it's on remember I said it on watch what happens when I 292 00:18:59,100 --> 00:19:01,250 flip it it sets it to off. 293 00:19:01,260 --> 00:19:08,310 So we're using an enumeration to handle on these related values and we can use enumerations to do all 294 00:19:08,310 --> 00:19:09,490 kinds of cool things. 295 00:19:09,510 --> 00:19:11,180 You can set associated values. 296 00:19:11,190 --> 00:19:18,660 You can set explicit types and raw values for those explicit type you can use tunnels and pass in those 297 00:19:18,750 --> 00:19:21,170 values to your associated types. 298 00:19:21,210 --> 00:19:26,160 You can do all kinds of really really cool stuff and there's much more if you dig into the Apple documentation 299 00:19:26,460 --> 00:19:28,140 on a numeration you can learn much more. 300 00:19:28,140 --> 00:19:32,400 But this is just kind of to cover the basics of enumerations and all they can do to help you. 301 00:19:32,400 --> 00:19:34,860 So let's go ahead and let's move over to the next video. 302 00:19:34,860 --> 00:19:36,500 This is Calleigh with slopes. 303 00:19:36,510 --> 00:19:36,910 Scott.