1 00:00:02,470 --> 00:00:03,860 Hey What's up everybody. 2 00:00:03,880 --> 00:00:06,840 Mark Price read Zepps slopes dot com. 3 00:00:07,010 --> 00:00:10,310 And today we're going to talk about numbers. 4 00:00:10,400 --> 00:00:14,730 You're like wait a minute I thought we were doing programming what the heck are we doing. 5 00:00:14,730 --> 00:00:18,370 Going back to like fifth grade math first grade. 6 00:00:18,390 --> 00:00:20,690 Whenever you learn about numbers probably in kindergarten. 7 00:00:21,270 --> 00:00:21,840 Yeah that's right. 8 00:00:21,840 --> 00:00:25,510 Today's episode is brought to you by the number three. 9 00:00:26,180 --> 00:00:26,610 OK. 10 00:00:26,760 --> 00:00:33,390 So really though open up your tax code better and create a new playground if you're following along. 11 00:00:33,390 --> 00:00:34,910 Otherwise you can just watch. 12 00:00:35,190 --> 00:00:41,510 And we're going to call this one numbers and I'm going to create a new folder for a year. 13 00:00:41,580 --> 00:00:44,740 It's always nice to organize your code and projects in the folders. 14 00:00:44,820 --> 00:00:50,810 Swift and this one's going to be called numbers or save it here. 15 00:00:50,810 --> 00:00:58,100 So numbers are a core foundational building block to any programming language. 16 00:00:58,100 --> 00:01:03,250 And when you think about it you interact with numbers all the time in any application that you're using. 17 00:01:03,320 --> 00:01:07,970 For instance if you go to Wells-Fargo dot com to log to your bank account you're going to see your bank 18 00:01:07,970 --> 00:01:09,700 account balance and has numbers in it. 19 00:01:09,830 --> 00:01:10,400 OK. 20 00:01:10,490 --> 00:01:17,450 If you are using a workout app and one week you weighed like 150 pounds in the next week you weighed 21 00:01:17,450 --> 00:01:22,780 170 pounds because who knows what you're doing with yourself. 22 00:01:22,850 --> 00:01:24,560 You have to use numbers to show that to the user. 23 00:01:24,560 --> 00:01:25,450 Numbers everywhere. 24 00:01:25,460 --> 00:01:30,680 And it had to do math in order to calculate how many calories you consume in all those different things. 25 00:01:30,680 --> 00:01:36,730 So numbers are everywhere and every application just like this is a string and there's words and applications 26 00:01:36,740 --> 00:01:37,150 OK. 27 00:01:37,580 --> 00:01:39,440 Use numbers and use words. 28 00:01:39,470 --> 00:01:44,320 I know it sounds basic but those are foundational variable types in any language. 29 00:01:44,330 --> 00:01:49,850 But there's different types of numbers so let's get rid of this string variable here and let's create 30 00:01:49,850 --> 00:01:51,730 a new variable. 31 00:01:52,110 --> 00:01:52,910 Some numbers. 32 00:01:52,910 --> 00:01:59,260 Right now we don't just say bar some number you know equals number. 33 00:01:59,270 --> 00:02:03,480 You know there's no what is the number you know there's no real number OK. 34 00:02:03,680 --> 00:02:10,760 Well you have to do is actually create different types of numbers such as integers floats and doubles 35 00:02:11,330 --> 00:02:12,280 and more. 36 00:02:12,350 --> 00:02:20,240 So for instance if it were a person write a program for a person maybe this is one of those apps that 37 00:02:20,800 --> 00:02:25,550 calc calculates and tracks calorie burning and things like that shows you how much junk food you're 38 00:02:25,560 --> 00:02:26,460 eating you know. 39 00:02:26,470 --> 00:02:30,160 So let's go ahead and say well we have to have a profile. 40 00:02:30,170 --> 00:02:42,600 So we have an age right or not or ago a person has an age will say age 30 and let's say var weight. 41 00:02:42,890 --> 00:02:44,120 Well that's two pounds. 42 00:02:44,250 --> 00:02:47,410 That's how we roll in the US of A weight equals. 43 00:02:47,430 --> 00:02:49,440 We're going to say 200. 44 00:02:49,440 --> 00:02:52,020 So this person weighs 200 pounds OK. 45 00:02:52,470 --> 00:02:56,230 Does anyone know what variable type this is. 46 00:02:56,520 --> 00:02:57,010 OK. 47 00:02:57,210 --> 00:03:04,440 Well these are actually called int or integers but in swift The key word is actually into like so. 48 00:03:04,440 --> 00:03:11,250 So what we can do here is I can put a colon here and then I can put in the keyword and the variable 49 00:03:11,250 --> 00:03:11,570 name. 50 00:03:11,580 --> 00:03:19,260 And what we're doing right here is creating an explicitly declared type before we were creating a variable 51 00:03:19,260 --> 00:03:23,420 with an inferred type meaning the variable is smart enough to know what you're putting in it. 52 00:03:23,430 --> 00:03:26,710 And so it knows that it's and knows that it's an event. 53 00:03:26,730 --> 00:03:31,180 For instance I can't say age equals peanuts. 54 00:03:31,200 --> 00:03:38,940 I have to try and break the program that cannot assign value of type string to type int. 55 00:03:39,180 --> 00:03:44,280 OK so you cannot put different data types inside of a variable and it was smart enough to know that 56 00:03:44,280 --> 00:03:45,300 this was an int. 57 00:03:45,300 --> 00:03:46,900 So this is the key word here. 58 00:03:47,190 --> 00:03:52,350 This is an inferred or let's call this type inference. 59 00:03:52,440 --> 00:03:55,170 That's the proper term type inference. 60 00:03:55,170 --> 00:03:56,580 It inferred what type it was. 61 00:03:56,580 --> 00:04:01,500 It's no different than this except it did automatically and by the way this is the recommended way in 62 00:04:01,500 --> 00:04:06,480 swift if at all possible use type inference and you have to use an explicit declaration to do it. 63 00:04:06,480 --> 00:04:09,500 Don't just do this because you think it looks nicer. 64 00:04:09,550 --> 00:04:14,210 That's not the swift way with boys like this but this is an explicitly declared type. 65 00:04:14,220 --> 00:04:15,000 OK. 66 00:04:15,560 --> 00:04:20,420 So this isn't explicitly declared type. 67 00:04:20,430 --> 00:04:24,150 Those are the key words and phrases right there explicitly declared because we actually wrote what type 68 00:04:24,150 --> 00:04:25,140 it was. 69 00:04:25,200 --> 00:04:30,880 And again the same thing here we can't say weight equals no way. 70 00:04:31,360 --> 00:04:33,760 We can't can't spell either. 71 00:04:34,140 --> 00:04:35,540 That's why we need to work with numbers. 72 00:04:35,660 --> 00:04:36,040 OK. 73 00:04:36,270 --> 00:04:37,170 So can't do it right. 74 00:04:37,200 --> 00:04:39,290 It's the same exact thing no difference. 75 00:04:39,450 --> 00:04:41,150 So pretty cool. 76 00:04:41,160 --> 00:04:43,330 So we've got we've got some in here. 77 00:04:43,530 --> 00:04:44,740 And what is an integer. 78 00:04:45,000 --> 00:04:45,840 OK what is an integer. 79 00:04:45,840 --> 00:04:48,750 Well let's go pull open the Swift book. 80 00:04:48,750 --> 00:04:53,840 If you don't have it already and if you don't have it please get it. 81 00:04:53,940 --> 00:04:55,990 Go to books. 82 00:04:56,070 --> 00:04:57,670 This is super important. 83 00:04:57,690 --> 00:04:59,490 Get this book if you don't have it. 84 00:04:59,670 --> 00:05:06,560 I said go to books were already in books and then do a search for swift not Dora the Explorer. 85 00:05:06,570 --> 00:05:10,330 Dora meets Pablo That's my personal reading just forget that you saw that. 86 00:05:10,530 --> 00:05:12,740 And the swift program blinked. 87 00:05:12,750 --> 00:05:14,900 How did that get on here. 88 00:05:15,210 --> 00:05:18,080 Anyway it's with three editions the one that you want. 89 00:05:18,660 --> 00:05:20,040 That's right. 90 00:05:20,340 --> 00:05:22,740 Right here don't do the one with cocoa and object. 91 00:05:22,760 --> 00:05:26,920 You do this right here and get that book and read through the entire thing. 92 00:05:26,940 --> 00:05:33,030 I promise you won't you won't regret it and I'll make him much better programmer so integers are whole 93 00:05:33,030 --> 00:05:39,870 numbers with no fractional component such as 42 and negative 23 integers are either signed positive 94 00:05:39,870 --> 00:05:43,610 zero negative or unsigned positive or zero. 95 00:05:43,800 --> 00:05:50,730 So if preside signed an unsigned injures and eight 16 32 and 64 bit forms and what that means is 64 96 00:05:50,730 --> 00:05:56,010 bit 32 bit it's how many characters how many digits it can hold the actual value. 97 00:05:56,240 --> 00:05:59,650 You know if someone had a trillion dollar bank account. 98 00:05:59,880 --> 00:06:04,440 You know you're probably not going to use this energy and use something larger but Swift is smart enough 99 00:06:04,440 --> 00:06:08,460 to do all that for you automatically just know that there are some different things going on under the 100 00:06:08,460 --> 00:06:09,030 hood. 101 00:06:09,390 --> 00:06:15,110 And so you can see some of the types here like you and eight OK and a 32 bit sign in terms of type into 102 00:06:15,200 --> 00:06:16,320 32. 103 00:06:16,320 --> 00:06:18,490 So it just depends. 104 00:06:18,500 --> 00:06:19,830 It shows how much it holds. 105 00:06:19,830 --> 00:06:25,590 Again you don't ever need to worry about this and pretty much in swift for the most part you're never 106 00:06:25,680 --> 00:06:29,770 ever going to have to do anything else except this standard. 107 00:06:29,940 --> 00:06:32,780 Ok but again you can you can do different things. 108 00:06:32,790 --> 00:06:41,590 You know some of them you know and you could say you can't or is it you want eight 16 32 64. 109 00:06:41,760 --> 00:06:43,380 Now you can do different things like that. 110 00:06:43,500 --> 00:06:44,730 OK. 111 00:06:45,330 --> 00:06:47,260 But you don't want to be careful. 112 00:06:47,370 --> 00:06:48,390 You know you don't want to. 113 00:06:48,390 --> 00:06:54,060 You don't want to do something that you can't you can't do because it will overflow the variable into 114 00:06:54,060 --> 00:06:58,800 your literal overflows when stored and you it's too big too big of a number. 115 00:06:58,860 --> 00:07:03,510 And so again don't play around with the zombie like oh I want to be more memory efficient and use smaller 116 00:07:03,570 --> 00:07:04,380 integers. 117 00:07:04,390 --> 00:07:05,250 Now don't do that. 118 00:07:05,250 --> 00:07:07,860 Always always always use it. 119 00:07:07,980 --> 00:07:08,460 OK. 120 00:07:08,580 --> 00:07:11,220 Always always always use an integer. 121 00:07:11,370 --> 00:07:13,780 I think actually this one is too big even for integer. 122 00:07:13,920 --> 00:07:23,350 So in this case you probably have to use a data type that even longer like a long or something Swift 123 00:07:23,410 --> 00:07:27,440 I think it's a double with that did the trick. 124 00:07:27,440 --> 00:07:32,680 There you go doubles double precision double twice as long. 125 00:07:32,740 --> 00:07:33,740 More or less. 126 00:07:33,900 --> 00:07:39,090 Anyway there is another data type which allows you to have incredibly long values here. 127 00:07:39,100 --> 00:07:39,450 OK. 128 00:07:39,490 --> 00:07:40,690 Look this is just huge. 129 00:07:40,690 --> 00:07:42,160 I don't even know what number that is. 130 00:07:42,160 --> 00:07:45,510 OK so we have integer which you want to use at any given time. 131 00:07:45,520 --> 00:07:53,580 If a number does not have decimal points and note nothing no dot you know whatever you want to use it. 132 00:07:53,590 --> 00:07:53,980 OK. 133 00:07:53,980 --> 00:07:57,310 Always always always use it if you need a long number. 134 00:07:57,310 --> 00:08:00,080 Double is the favorite choice here. 135 00:08:00,220 --> 00:08:00,930 OK. 136 00:08:01,240 --> 00:08:04,790 So you can also double. 137 00:08:04,840 --> 00:08:05,830 This is cool. 138 00:08:06,280 --> 00:08:08,140 If you had something like let's say a bank account right. 139 00:08:08,140 --> 00:08:11,430 So actually no we're doing what are we doing here. 140 00:08:11,470 --> 00:08:15,570 We're doing an exercise Apso let's say Miles ran OK. 141 00:08:15,640 --> 00:08:18,970 Our Miles ran and we ran. 142 00:08:19,270 --> 00:08:20,230 Equals. 143 00:08:20,470 --> 00:08:21,410 We've run in the whole week. 144 00:08:21,410 --> 00:08:24,610 Fifty six point four five miles. 145 00:08:24,610 --> 00:08:27,610 So what type is this. 146 00:08:27,620 --> 00:08:31,290 This is actually a double. 147 00:08:31,720 --> 00:08:32,230 That's pretty cool. 148 00:08:32,230 --> 00:08:36,520 So by default swift uses doubles which has double the precision. 149 00:08:36,520 --> 00:08:41,690 In fact let's Ballman our handy dandy book here like I didn't pay X amount of dollars for this course 150 00:08:41,700 --> 00:08:42,970 or you can read a book to me. 151 00:08:43,030 --> 00:08:45,780 I wanted you to say those words without looking at a book. 152 00:08:46,060 --> 00:08:47,470 Does it make any sense. 153 00:08:47,470 --> 00:08:50,090 No it's better to have it straight from the horse's mouth. 154 00:08:50,110 --> 00:08:51,140 And I do this a lot. 155 00:08:51,290 --> 00:08:52,600 Get used to it. 156 00:08:52,600 --> 00:08:54,600 It is so important to read the documentation. 157 00:08:54,670 --> 00:08:58,710 Like seriously if you go to your boss every single day like how do you do this how do you do this he's 158 00:08:58,720 --> 00:08:59,620 going to fire you. 159 00:08:59,770 --> 00:09:02,850 I wouldn't have an employee like that you've got to learn how to learn. 160 00:09:02,860 --> 00:09:04,330 So always go back to the documentation. 161 00:09:04,330 --> 00:09:08,310 I'm trying to train you here how to be a lifelong learner and programmer. 162 00:09:08,320 --> 00:09:13,710 So where was I before I started lecturing you on things you don't even care about. 163 00:09:14,180 --> 00:09:14,390 OK. 164 00:09:14,400 --> 00:09:19,870 So we talk about integers now come floating point numbers floating point numbers or numbers with a fractional 165 00:09:19,870 --> 00:09:24,700 component such as 3.1 for maybe you're thinking wait you just did double wide. 166 00:09:24,870 --> 00:09:25,980 Why. 167 00:09:26,170 --> 00:09:28,060 Why didn't we do a float with the decimals. 168 00:09:28,060 --> 00:09:32,590 Well read this double as a precision of at least 15 decimal digits. 169 00:09:32,590 --> 00:09:34,480 OK so 15 decimal digits. 170 00:09:34,530 --> 00:09:37,850 Where is the precision of a flow can be as little as six decimal digits. 171 00:09:37,930 --> 00:09:42,040 The appropriate floating point type to use depends on the nature and range of values you need to work 172 00:09:42,040 --> 00:09:43,000 with in your code. 173 00:09:43,270 --> 00:09:47,770 In situations where either type would be appropriate double is preferred. 174 00:09:47,780 --> 00:09:50,110 OK so by default swift uses double. 175 00:09:50,330 --> 00:09:53,680 OK as you can tell it's a 64 bit floating point number. 176 00:09:53,680 --> 00:09:59,380 Very long a float cannot be as big and maybe you think it will should make the numbers I should say 177 00:09:59,380 --> 00:10:03,190 memory by using a flow and have a double no switch just I optimized under the hood. 178 00:10:03,500 --> 00:10:06,360 And it recommends that use double overflow and at a given time. 179 00:10:06,370 --> 00:10:09,070 So don't use a float unless you absolutely have to. 180 00:10:09,070 --> 00:10:12,010 Whereas in other languages float is the keyword in swift. 181 00:10:12,010 --> 00:10:14,130 Always use double double double double. 182 00:10:14,470 --> 00:10:15,170 OK. 183 00:10:15,450 --> 00:10:19,040 So just to show you that this is a double by default. 184 00:10:19,180 --> 00:10:26,950 If we do create a float let's say var pi equals three point one for k and then I say Miles Rand equals 185 00:10:27,280 --> 00:10:30,200 PI and for pi. 186 00:10:30,350 --> 00:10:33,000 Let's see what happens. 187 00:10:33,090 --> 00:10:38,790 Actually this is going to work because the double the flow will convert to double what I meant to do 188 00:10:39,150 --> 00:10:41,430 was pi equals milestone 189 00:10:45,250 --> 00:10:48,380 actually works interchangeably news to me. 190 00:10:48,400 --> 00:10:48,720 OK. 191 00:10:48,730 --> 00:10:54,960 So this is definitely a float though. 192 00:10:55,030 --> 00:10:55,840 Oh that's why. 193 00:10:56,020 --> 00:10:58,410 Ok guys I'm not smoking crack I promise. 194 00:10:58,450 --> 00:11:01,540 This is a it's because it was both a double and like tripping out. 195 00:11:01,560 --> 00:11:02,970 Why is it not working. 196 00:11:02,980 --> 00:11:03,430 OK. 197 00:11:03,580 --> 00:11:05,080 So there you go. 198 00:11:05,590 --> 00:11:05,800 OK. 199 00:11:05,810 --> 00:11:07,750 So pi is a float. 200 00:11:07,750 --> 00:11:08,430 Here we go. 201 00:11:08,470 --> 00:11:10,900 Can assign value of type double to type float. 202 00:11:10,900 --> 00:11:13,180 So clearly this is a double. 203 00:11:13,180 --> 00:11:14,460 And clearly this is a float. 204 00:11:14,560 --> 00:11:18,370 So the point I was trying to make is by default it always chooses a double when you use the decimal 205 00:11:18,370 --> 00:11:19,160 points. 206 00:11:19,240 --> 00:11:23,200 And so when you're creating your apps you're only going to really ever use and doubles for the most 207 00:11:23,200 --> 00:11:26,330 part when you're working with numbers which is really cool. 208 00:11:26,830 --> 00:11:35,380 And I encourage you to actually read a whole lot more in this swift book about wherever it went about 209 00:11:35,680 --> 00:11:40,570 all these different things because they has incredibly valuable information incredibly valuable and 210 00:11:40,570 --> 00:11:46,870 it's actually Britain written with the proper keywords because sometimes you may hear an instructor 211 00:11:46,870 --> 00:11:50,440 or somebody talking about programming in general they're not using the right terms or summarizing it 212 00:11:50,440 --> 00:11:54,790 Swift actually in those books they actually use the right keywords and they teach what's going on under 213 00:11:54,790 --> 00:12:00,600 the hood in a lot of cases so those numbers right and you can do a lot of things with numbers. 214 00:12:00,940 --> 00:12:04,090 And we talked in the earlier video about operators. 215 00:12:04,660 --> 00:12:07,280 You're going to use what's called a rith. 216 00:12:07,500 --> 00:12:12,050 Take my math. 217 00:12:12,460 --> 00:12:13,240 Oh my gosh. 218 00:12:13,330 --> 00:12:18,900 I'm sorry I just the arithmetic arithmetic. 219 00:12:18,910 --> 00:12:20,560 All right. 220 00:12:20,680 --> 00:12:26,120 Rith lactic arithmetic operators. 221 00:12:27,680 --> 00:12:31,450 If you're new to the class and you're wondering like why does he why does he leave some of the stuff 222 00:12:31,450 --> 00:12:34,870 in here like why do we make mistakes and things like that. 223 00:12:34,960 --> 00:12:37,470 And what happened was in the beginning I didn't always do that. 224 00:12:37,480 --> 00:12:40,620 I kind of cleaned up the code and made it look perfect. 225 00:12:40,630 --> 00:12:43,380 Sounds like you're doing it so perfectly. 226 00:12:43,540 --> 00:12:44,850 You're just so amazing. 227 00:12:44,860 --> 00:12:47,910 I'm never going to be a programmer because you can't do it perfectly. 228 00:12:47,940 --> 00:12:49,800 And I was it guys and gals. 229 00:12:49,870 --> 00:12:51,320 I'm not doing it perfectly. 230 00:12:51,340 --> 00:12:52,200 This is all edited. 231 00:12:52,200 --> 00:12:56,000 So I started making videos that were real like how programmers really solve problems. 232 00:12:56,020 --> 00:12:58,170 And then everyone's like I can do this. 233 00:12:58,210 --> 00:13:02,090 Mark prizes he's not a robot he's a real person who has to figure things out and use his brain. 234 00:13:02,110 --> 00:13:03,130 And that's why we do these things. 235 00:13:03,130 --> 00:13:08,080 That's why these videos are so informal because I pretend that you're sitting here right next to me 236 00:13:08,080 --> 00:13:11,460 in the class so I can actually teach and convey a message to you. 237 00:13:11,470 --> 00:13:13,900 So again if you're new to all this this is how we do it. 238 00:13:13,900 --> 00:13:16,650 All right dev slopes and it's exciting and people love it. 239 00:13:16,780 --> 00:13:20,290 If you hate it I'm sorry I just love it. 240 00:13:20,290 --> 00:13:20,520 OK. 241 00:13:20,530 --> 00:13:24,450 So arithmetic operators you know and this is just like in math and in high school right. 242 00:13:24,460 --> 00:13:25,570 Or grade school. 243 00:13:25,590 --> 00:13:25,950 Right. 244 00:13:26,020 --> 00:13:33,270 You know you get plus minus divide multiplication and things like that. 245 00:13:33,310 --> 00:13:37,780 And so you can actually you can actually play around with numbers which is kind of cool. 246 00:13:37,790 --> 00:13:42,280 One of my favorite ones is like doing the area of a shape or a rectangle. 247 00:13:42,280 --> 00:13:49,310 So a bar area equals and let's say lengths of 15 times with 20. 248 00:13:49,320 --> 00:13:49,830 OK. 249 00:13:50,140 --> 00:13:55,830 And we just did multiplication 315 times 20 which is really cool. 250 00:13:56,020 --> 00:13:57,530 And we can do addition as well. 251 00:13:57,550 --> 00:14:09,270 Var some equals five plus six bar diff for difference equals 10 minus 3 32 10 minus 3. 252 00:14:09,520 --> 00:14:12,830 And so we're doing different operations here which is really cool. 253 00:14:13,120 --> 00:14:13,900 What about division. 254 00:14:13,900 --> 00:14:14,790 Can we do division. 255 00:14:14,820 --> 00:14:27,910 Well yes we can we can say let's say 12 divided by groups some division 12 divided by three is four. 256 00:14:27,910 --> 00:14:28,520 OK. 257 00:14:28,930 --> 00:14:31,160 But there's one more thing I want to show you. 258 00:14:31,170 --> 00:14:32,940 OK. 259 00:14:33,370 --> 00:14:38,950 What if you said bar divide and we said what is 12 divided by five. 260 00:14:40,790 --> 00:14:46,550 Do you think it's going to be Hoopes this one equals 12 divided by five. 261 00:14:46,560 --> 00:14:48,360 And again these are just container names were given them. 262 00:14:48,360 --> 00:14:49,230 OK. 263 00:14:49,740 --> 00:14:51,210 So wait a minute. 264 00:14:51,360 --> 00:14:53,940 Twelve divided by five is not two words the remainder. 265 00:14:53,940 --> 00:15:00,230 There's got to be a remainder well in swift and pretty much every other programming language division 266 00:15:00,450 --> 00:15:03,460 or the arithmetic operator for division. 267 00:15:03,540 --> 00:15:11,880 This backslash here is only going to do the division and only give you how many times it goes into a 268 00:15:11,880 --> 00:15:12,250 number. 269 00:15:12,270 --> 00:15:14,650 The remainder actually is not going to be provided to you. 270 00:15:14,670 --> 00:15:21,630 So to get the remainder you actually have to use what's called the remainder operator or modulo or modulus. 271 00:15:21,630 --> 00:15:27,210 I've heard people say all kinds of things in called the modulo operators commonly use or the remainder 272 00:15:27,210 --> 00:15:30,330 operator that's what Swift calls the remainder operator. 273 00:15:30,330 --> 00:15:36,670 So the remainder operator is this equals 12 percent sign 5. 274 00:15:36,930 --> 00:15:40,480 OK so which is two. 275 00:15:40,500 --> 00:15:44,930 There's two of a remainder OK writes of five goes in the 12 two times with the remainder of two. 276 00:15:45,060 --> 00:15:51,030 In fact let's do 13 just to show you that these are different numbers here OK. 277 00:15:51,120 --> 00:15:56,070 So so if I wanted to show the full problem OK I could do something like this. 278 00:15:56,070 --> 00:15:59,930 Var result equals. 279 00:15:59,970 --> 00:16:00,920 This is gonna be a string right. 280 00:16:00,920 --> 00:16:09,600 So the result of 13 divided by five is OK. 281 00:16:10,290 --> 00:16:21,300 We can use string Interpol action here OK to insert a variable in and we can say Div 1 and we'll say 282 00:16:21,310 --> 00:16:28,370 dot for the decimal right with the remainder of. 283 00:16:29,160 --> 00:16:29,980 Not really. 284 00:16:30,000 --> 00:16:31,740 It's not really appropriate. 285 00:16:31,830 --> 00:16:41,530 5 is with a remainder of Arrigo and then we'll put in the remainder. 286 00:16:42,060 --> 00:16:48,660 So the result of 13 divided by five is to with a remainder of three. 287 00:16:48,890 --> 00:16:49,440 OK. 288 00:16:49,680 --> 00:16:51,530 And don't worry if you don't understand all this just yet. 289 00:16:51,570 --> 00:16:53,640 I'm just inserting variables into my string. 290 00:16:53,640 --> 00:16:55,490 Here's the print out to the screen. 291 00:16:55,530 --> 00:16:57,730 So what happens with the remainder operator. 292 00:16:57,750 --> 00:16:59,160 Is it going to do the division. 293 00:16:59,340 --> 00:17:02,310 But instead of returning the first number it's going returned the remainder. 294 00:17:02,310 --> 00:17:11,190 If there is a remainder and this is a great way to determine what numbers are even or odd even numbers 295 00:17:11,460 --> 00:17:16,980 will have no remainder I say if I wanted to know if number was even or odd slow say bar random number 296 00:17:17,400 --> 00:17:19,140 equals 13. 297 00:17:19,140 --> 00:17:25,800 So we can say if random number modulo two equals zero. 298 00:17:25,800 --> 00:17:29,930 So the double equal sign is this something is something true or false you know. 299 00:17:29,970 --> 00:17:32,620 Or is this equal to that it's going to give you a boolean value. 300 00:17:32,700 --> 00:17:40,590 So if random number modulo or remainder operator two equals zero OK you know will print. 301 00:17:40,620 --> 00:17:43,340 This is an even number. 302 00:17:43,980 --> 00:17:45,230 All right. 303 00:17:45,300 --> 00:17:50,950 Else this is an odd number. 304 00:17:51,700 --> 00:17:52,510 OK. 305 00:17:53,020 --> 00:17:54,240 And so look it's printing up. 306 00:17:54,230 --> 00:17:57,560 This is an odd number but what if we turn this to 12. 307 00:17:57,620 --> 00:17:58,160 OK. 308 00:17:58,260 --> 00:17:59,400 So this is an even number. 309 00:17:59,400 --> 00:18:03,740 So this is something that is very commonly used to determine whether numbers are even or odd. 310 00:18:03,750 --> 00:18:04,640 Is this remainder. 311 00:18:04,650 --> 00:18:05,420 Operator. 312 00:18:05,490 --> 00:18:07,500 So you've done some basic arithmetic. 313 00:18:07,530 --> 00:18:11,470 We've talked about different types here like and double and low. 314 00:18:11,520 --> 00:18:15,380 You can use negative numbers you can use positive numbers. 315 00:18:15,480 --> 00:18:17,320 You can do all kinds of fun things. 316 00:18:17,320 --> 00:18:18,610 All right. 317 00:18:18,690 --> 00:18:25,280 And by the way this right here this is a very operator kind of like what we've talked about in the past. 318 00:18:25,410 --> 00:18:28,640 It's operating on one target here making a negative number here. 319 00:18:28,710 --> 00:18:32,510 Just so you know we'll well tip and trick right there. 320 00:18:32,700 --> 00:18:37,110 And so don't worry too much about the ifs analysis you don't understand that just yet or the string 321 00:18:37,200 --> 00:18:42,330 into position that we used here the point of this lesson is to talk about numbers you can do math operations 322 00:18:42,420 --> 00:18:48,510 and of course order of operations are all followed in swift as well as most other programming languages 323 00:18:48,520 --> 00:18:51,420 so I can save our results. 324 00:18:51,420 --> 00:18:54,350 Two equals let's say 15 times. 325 00:18:54,360 --> 00:18:58,670 Five plus seven divided by three. 326 00:18:58,860 --> 00:18:59,170 All right. 327 00:18:59,220 --> 00:19:06,300 And if I want a five and seven to be done first and then I wanted the result of this to be done next 328 00:19:08,100 --> 00:19:08,910 I could do something like that. 329 00:19:08,910 --> 00:19:16,140 So just like you do in math like in high school the order of operations you know still applies the same 330 00:19:16,140 --> 00:19:19,020 that you would do in math in high school and you can use parentheses just like you would do in high 331 00:19:19,020 --> 00:19:23,180 school math to get the results that you are looking for. 332 00:19:23,190 --> 00:19:24,860 And again this is very foundational. 333 00:19:24,860 --> 00:19:30,180 Every app you've ever used uses math like this when you're swiping your card at a bank and it wants 334 00:19:30,180 --> 00:19:35,210 to deduct money it's got to use math to take money out of your bank account things like that. 335 00:19:35,280 --> 00:19:41,000 So you have now used a basic foundational thing that you can use for the rest of your life as a programmer 336 00:19:41,130 --> 00:19:43,210 and in every house that you'll ever build. 337 00:19:43,690 --> 00:19:44,880 So that's it. 338 00:19:44,880 --> 00:19:48,320 Numbers mark up slopes dot com. 339 00:19:48,350 --> 00:19:48,980 See you next.