1 00:00:02,540 --> 00:00:03,800 Hey What's up everybody. 2 00:00:03,830 --> 00:00:10,750 Mark Price here at the slopes a dot com and today we're going to talk about numbers and you're like 3 00:00:11,320 --> 00:00:14,680 wait a minute I thought we were doing programming what the heck are we doing. 4 00:00:14,680 --> 00:00:20,650 Going back to like fifth grade math first grade whenever you can but numbers probably in kindergarten. 5 00:00:21,220 --> 00:00:21,790 Yeah that's right. 6 00:00:21,790 --> 00:00:25,450 Today's episode is brought to you by the number three. 7 00:00:26,110 --> 00:00:26,560 OK. 8 00:00:26,710 --> 00:00:33,310 So really though open up your excavator and create a new playground if you're following along. 9 00:00:33,310 --> 00:00:35,050 Otherwise you can just watch. 10 00:00:35,140 --> 00:00:41,460 And we're going to call this one numbers and I'm going to create a new folder for a year. 11 00:00:41,530 --> 00:00:44,690 It's always nice to organize your code and projects in the folders. 12 00:00:44,770 --> 00:00:50,710 Swift and this one is going to be called numbers or to save it here. 13 00:00:50,770 --> 00:00:57,970 So numbers are a core foundational building block to any programming language. 14 00:00:58,030 --> 00:01:03,180 And when you think about it you interact with numbers all the time in any application that you're using. 15 00:01:03,250 --> 00:01:07,660 For instance if you go to Wells-Fargo dot com to log into your bank account you're going to see your 16 00:01:07,660 --> 00:01:09,670 bank account balance and has numbers in it. 17 00:01:09,790 --> 00:01:10,340 OK. 18 00:01:10,420 --> 00:01:17,390 If you are using a workout app and one week you weighed like 150 pounds in the next week you weight 19 00:01:17,410 --> 00:01:22,190 170 pounds because who knows what you're doing with yourself. 20 00:01:22,810 --> 00:01:24,490 You have to use numbers to show that to the user. 21 00:01:24,490 --> 00:01:25,380 Numbers are everywhere. 22 00:01:25,390 --> 00:01:30,610 And it had to do math in order to calculate how many calories you consume in all those different things. 23 00:01:30,610 --> 00:01:36,690 So numbers are everywhere and every application just like this is a string and there's words and applications 24 00:01:36,710 --> 00:01:39,390 OK use numbers and use words. 25 00:01:39,400 --> 00:01:44,280 I know it sounds basic but those are foundational variable types in any language. 26 00:01:44,290 --> 00:01:49,810 But there's different types of numbers so let's get rid of this string variable here and let's create 27 00:01:49,810 --> 00:01:51,910 a new variable. 28 00:01:52,060 --> 00:01:52,810 Some numbers. 29 00:01:52,810 --> 00:01:59,210 Right now we don't just say bar some number you know equals number. 30 00:01:59,230 --> 00:02:02,860 You know there's no what is the number you know there's no real number. 31 00:02:02,860 --> 00:02:03,460 OK. 32 00:02:03,640 --> 00:02:10,690 Well you have to do is actually create different types of numbers such as integers floats and doubles 33 00:02:11,270 --> 00:02:12,050 and is more. 34 00:02:12,310 --> 00:02:20,170 So for instance if it were a person write a program for a person maybe this is one of those apps that 35 00:02:20,760 --> 00:02:25,870 cak calculates and tracks calorie burning and things like that shows you how much junk food you're eating 36 00:02:26,050 --> 00:02:26,390 you know. 37 00:02:26,390 --> 00:02:30,100 So let's go ahead and say well we have to have a profile. 38 00:02:30,100 --> 00:02:42,540 So we have an age right or not origo a person has an age to say age 30 and let's say var weight. 39 00:02:42,840 --> 00:02:44,070 Well that's two pounds. 40 00:02:44,200 --> 00:02:49,390 That's how we roll in the US of A weight equals we're going to say 200. 41 00:02:49,390 --> 00:02:51,180 So this person weighs 200 pounds. 42 00:02:51,190 --> 00:02:51,990 OK. 43 00:02:52,420 --> 00:02:56,410 Does anyone know what variable type this is. 44 00:02:56,470 --> 00:02:56,960 OK. 45 00:02:57,160 --> 00:03:04,320 Well these are actually called int or integers but in swift The key word is actually into like so. 46 00:03:04,340 --> 00:03:11,200 So what we can do here is I can put a colon here and then I can put in the keyword and the variable 47 00:03:11,200 --> 00:03:11,530 name. 48 00:03:11,530 --> 00:03:19,210 And what we're doing right here is creating an explicitly declared type before we were creating a variable 49 00:03:19,210 --> 00:03:23,370 with an inferred type meaning the variable is smart enough to know what you're putting in it. 50 00:03:23,380 --> 00:03:26,630 And so it knows that it's and knows that it's an event. 51 00:03:26,650 --> 00:03:31,130 For instance I can't say age equals peanuts. 52 00:03:31,180 --> 00:03:39,130 I have to try and break the program that cannot assign value of type string to type int. 53 00:03:39,130 --> 00:03:44,230 OK so you cannot put different data types inside of a variable and it was smart enough to know that 54 00:03:44,230 --> 00:03:45,240 this was an int. 55 00:03:45,250 --> 00:03:46,860 So this is the key word here. 56 00:03:47,140 --> 00:03:52,320 This is an inferred or let's just call this type inference. 57 00:03:52,390 --> 00:03:55,100 That's the proper term type inference. 58 00:03:55,120 --> 00:03:56,530 It inferred what type it was. 59 00:03:56,540 --> 00:04:01,450 It's no different than this except it did automatically and by the way this is the recommended way in 60 00:04:01,450 --> 00:04:06,640 swift if at all possible use type inference and if you have to use an explicit declaration do it don't 61 00:04:06,640 --> 00:04:09,500 just do this because you think it looks nicer. 62 00:04:09,500 --> 00:04:14,150 That's not the swift way with boys like this but this is an explicitly declared type. 63 00:04:14,170 --> 00:04:14,910 OK. 64 00:04:15,520 --> 00:04:20,370 So this isn't explicitly declared type. 65 00:04:20,370 --> 00:04:24,100 Those are the key words and phrases right there explicitly declared because we actually wrote what type 66 00:04:24,100 --> 00:04:25,090 it was. 67 00:04:25,150 --> 00:04:30,820 And again the same thing here we can't say Wait equals no way. 68 00:04:31,090 --> 00:04:33,710 All right we can't can't spell either. 69 00:04:34,090 --> 00:04:35,520 That's why we need to work with numbers. 70 00:04:35,640 --> 00:04:35,990 OK. 71 00:04:36,220 --> 00:04:37,120 So can't do it right. 72 00:04:37,140 --> 00:04:39,230 It's the same exact thing no difference. 73 00:04:39,400 --> 00:04:41,110 So pretty cool. 74 00:04:41,110 --> 00:04:43,250 So we've got we've got some int here. 75 00:04:43,480 --> 00:04:44,690 And what is an integer. 76 00:04:44,950 --> 00:04:45,790 OK what is an integer. 77 00:04:45,800 --> 00:04:48,700 Well let's go pull open the Swift book. 78 00:04:48,700 --> 00:04:53,860 If you don't have it already and if you don't have it please get it. 79 00:04:53,860 --> 00:04:55,920 Go to books. 80 00:04:56,020 --> 00:04:57,640 This is super important. 81 00:04:57,640 --> 00:04:59,450 Get this book if you don't have it. 82 00:04:59,620 --> 00:05:06,510 I said go to books were already in books and then do a search for swift not Dora the Explorer. 83 00:05:06,520 --> 00:05:10,330 Dora meets Pablo That's my personal reading just forget that you saw that. 84 00:05:10,480 --> 00:05:12,690 And the swift program mealing. 85 00:05:12,700 --> 00:05:15,700 How did that get on here anyway. 86 00:05:15,820 --> 00:05:18,030 Swift three editions the one that you want. 87 00:05:18,610 --> 00:05:19,890 That's right. 88 00:05:20,170 --> 00:05:22,730 Right here don't do the one with Coco an object. 89 00:05:22,750 --> 00:05:26,820 You do this right here and get that book and read through the entire thing. 90 00:05:26,890 --> 00:05:32,950 I promise you won't you won't regret it and I'll make you a much better programmer so integers are whole 91 00:05:32,950 --> 00:05:39,820 numbers with no fractional component such as 42 and negative 23 integers are either signed positive 92 00:05:39,820 --> 00:05:43,530 zero or negative or unsigned positive or zero. 93 00:05:43,710 --> 00:05:48,990 So if preside signed an unsigned integers and 8 16 32 and 64 bit forums. 94 00:05:49,210 --> 00:05:55,120 And what that means is 64 bit 32 bit it's how many characters how many digits it can hold the actual 95 00:05:55,120 --> 00:05:55,900 value. 96 00:05:56,030 --> 00:06:01,570 You know if someone had a trillion dollar bank account you know you're probably not going to use this 97 00:06:02,050 --> 00:06:06,310 energy and use something larger but Swift is smart enough to do all that for you automatically just 98 00:06:06,310 --> 00:06:08,990 know that there are some different things going on under the hood. 99 00:06:09,340 --> 00:06:12,350 And so you can see some of the types here like you and Kate. 100 00:06:12,520 --> 00:06:12,990 OK. 101 00:06:13,000 --> 00:06:16,200 And a 32 bit sign in terms of type in 2:32. 102 00:06:16,270 --> 00:06:18,450 So it just depends. 103 00:06:18,460 --> 00:06:19,780 It shows how much it holds. 104 00:06:19,790 --> 00:06:25,840 Again you don't ever need to worry about this pretty much in swift for the most part you're never ever 105 00:06:25,840 --> 00:06:29,720 going to have to do anything else except this standard. 106 00:06:29,890 --> 00:06:32,730 Ok but again you can you can do different things. 107 00:06:32,740 --> 00:06:38,720 You know some them you know and you could say you can't or is it you. 108 00:06:39,250 --> 00:06:41,590 Eight 16 32 64. 109 00:06:41,740 --> 00:06:43,330 Now you can do different things like that. 110 00:06:43,450 --> 00:06:44,660 OK. 111 00:06:45,280 --> 00:06:47,210 But you don't want to be careful. 112 00:06:47,320 --> 00:06:48,190 You know you don't want to. 113 00:06:48,330 --> 00:06:50,340 You don't want to do something that you can't. 114 00:06:50,350 --> 00:06:56,190 You can't do it because it will overflow the variable into your literal overflows when stored in you 115 00:06:56,240 --> 00:06:58,740 it's too big too big of a number. 116 00:06:58,810 --> 00:07:03,460 And so again don't play around with the zombie like oh I want to be more memory efficient and use smaller 117 00:07:03,520 --> 00:07:04,320 integers. 118 00:07:04,340 --> 00:07:05,200 Now don't do that. 119 00:07:05,200 --> 00:07:07,810 Always always always use it. 120 00:07:07,930 --> 00:07:08,410 OK. 121 00:07:08,530 --> 00:07:11,150 Always always always use an integer. 122 00:07:11,320 --> 00:07:13,730 I think actually this one is too big even for integer. 123 00:07:13,870 --> 00:07:23,290 So in this case you probably have to use a data type that even longer like a long or something Swift 124 00:07:23,350 --> 00:07:27,560 I think it's a double that did the trick. 125 00:07:27,560 --> 00:07:32,650 There you go doubles double precision double to twice as long. 126 00:07:32,690 --> 00:07:33,580 More or less. 127 00:07:33,810 --> 00:07:38,970 Anyway there is another data type which allows you to have incredibly long values here. 128 00:07:39,050 --> 00:07:39,410 OK. 129 00:07:39,450 --> 00:07:40,640 Look this is just huge. 130 00:07:40,640 --> 00:07:42,110 I don't even know what number that is. 131 00:07:42,110 --> 00:07:45,440 OK so we have integer which you want to use at any given time. 132 00:07:45,470 --> 00:07:49,260 If a number does not have decimal points a note nothing. 133 00:07:49,310 --> 00:07:50,740 No dot. 134 00:07:50,820 --> 00:07:53,490 You know whatever you want to use it. 135 00:07:53,510 --> 00:07:53,930 OK. 136 00:07:53,930 --> 00:07:57,260 Always always always use it if you need a long number. 137 00:07:57,260 --> 00:08:00,030 Double is the favorite choice here. 138 00:08:00,170 --> 00:08:00,840 OK. 139 00:08:01,190 --> 00:08:04,790 So you can also on double. 140 00:08:04,790 --> 00:08:05,750 This is cool. 141 00:08:06,200 --> 00:08:08,090 If you had something like let's say a bank account right. 142 00:08:08,090 --> 00:08:11,370 So actually no we're doing what are we doing here. 143 00:08:11,420 --> 00:08:13,260 We're doing an exercise. 144 00:08:13,270 --> 00:08:18,940 So let's say Miles ran our miles ran and we ran. 145 00:08:19,220 --> 00:08:20,100 Equals. 146 00:08:20,420 --> 00:08:21,340 We've run in the whole week. 147 00:08:21,350 --> 00:08:24,550 Fifty six point four five miles. 148 00:08:24,560 --> 00:08:27,550 So what type is this. 149 00:08:27,570 --> 00:08:31,670 This is actually a double. 150 00:08:31,670 --> 00:08:32,180 That's pretty cool. 151 00:08:32,180 --> 00:08:36,470 So by default swift uses doubles which has double the precision. 152 00:08:36,470 --> 00:08:41,690 In fact let's pull our handy dandy book here like I didn't pay X amount of dollars for this course or 153 00:08:41,690 --> 00:08:42,920 you can read a book to me. 154 00:08:42,980 --> 00:08:45,730 I wanted you to say those words without looking at a book. 155 00:08:46,000 --> 00:08:47,420 Does that make any sense. 156 00:08:47,420 --> 00:08:50,040 No it's better to have it straight from the horse's mouth. 157 00:08:50,060 --> 00:08:51,230 And I do this a lot. 158 00:08:51,250 --> 00:08:52,550 Get used to it. 159 00:08:52,550 --> 00:08:54,560 It is so important to read the documentation. 160 00:08:54,620 --> 00:08:58,650 Like seriously if you go to your boss every single day like how do you do this how do you do this you're 161 00:08:58,670 --> 00:08:59,570 going to fire you. 162 00:08:59,720 --> 00:09:02,800 I wouldn't have an employee like that you've got to learn how to learn. 163 00:09:02,810 --> 00:09:04,280 So always go back to the documentation. 164 00:09:04,280 --> 00:09:08,260 I'm trying to train you here how to be a lifelong learner and programmer. 165 00:09:08,270 --> 00:09:13,670 So where was I before I started lecturing you on things you really didn't care about. 166 00:09:14,130 --> 00:09:14,330 OK. 167 00:09:14,340 --> 00:09:15,860 So we talked about integers. 168 00:09:16,070 --> 00:09:16,630 OK. 169 00:09:17,030 --> 00:09:21,690 Floating point numbers floating point numbers or numbers with a fractional component such as 3.1 for 170 00:09:22,190 --> 00:09:24,580 maybe you're thinking wait you just did double wide. 171 00:09:24,640 --> 00:09:25,880 Why. 172 00:09:26,120 --> 00:09:28,000 Why didn't we do a float with the decimals. 173 00:09:28,010 --> 00:09:32,540 Well read this double as a precision of at least 15 decimal digits. 174 00:09:32,540 --> 00:09:34,430 OK so 15 decimal digits. 175 00:09:34,490 --> 00:09:37,780 Where is the precision of a flow can be as little as six decimal digits. 176 00:09:37,850 --> 00:09:41,990 The appropriate floating point type to use depends on the nature and range of values you need to work 177 00:09:41,990 --> 00:09:42,940 with in your code. 178 00:09:43,220 --> 00:09:47,650 In situations where either type would be appropriate double is preferred. 179 00:09:47,730 --> 00:09:50,020 OK so by default swift uses double. 180 00:09:50,250 --> 00:09:50,630 OK. 181 00:09:50,630 --> 00:09:53,630 As you can tell it's a 64 bit floating point number. 182 00:09:53,630 --> 00:09:59,330 Very long a float cannot be as big and maybe you think it will I should make the numbers I should say 183 00:09:59,340 --> 00:10:03,010 memory by using a flow and have a double no switch is I optimized under the hood. 184 00:10:03,010 --> 00:10:06,320 And and it recommends that use double overflow and at a given time. 185 00:10:06,320 --> 00:10:09,020 So don't use a float unless you absolutely have to. 186 00:10:09,020 --> 00:10:11,920 Whereas in other languages float is the keyword in swift. 187 00:10:11,940 --> 00:10:14,010 Always use double double double double. 188 00:10:14,420 --> 00:10:15,100 OK. 189 00:10:15,380 --> 00:10:18,980 So just to show you that this is a double by default. 190 00:10:19,130 --> 00:10:26,900 If we do create a float let's say var pi equals three point one for k and then I say Miles Rand equals 191 00:10:27,230 --> 00:10:28,410 pi. 192 00:10:28,630 --> 00:10:30,350 I ran for pi. 193 00:10:30,370 --> 00:10:31,460 See what happens. 194 00:10:33,040 --> 00:10:38,740 Actually this is going to work because the double the flow will convert to double what I meant to do 195 00:10:39,100 --> 00:10:41,380 was pi equals milestone 196 00:10:45,200 --> 00:10:47,010 actually works interchangeably. 197 00:10:47,330 --> 00:10:48,330 News to me. 198 00:10:48,360 --> 00:10:54,890 OK so this is definitely a float though. 199 00:10:54,990 --> 00:10:55,790 Oh that's why. 200 00:10:55,970 --> 00:10:58,400 Ok guys I'm not smoking crack I promise. 201 00:10:58,420 --> 00:11:01,540 This is a it's because it was both a double and like tripping out. 202 00:11:01,540 --> 00:11:02,910 Why is it not working. 203 00:11:02,930 --> 00:11:03,530 OK. 204 00:11:03,530 --> 00:11:05,010 So there you go. 205 00:11:05,510 --> 00:11:05,750 OK. 206 00:11:05,760 --> 00:11:07,700 So pi is a float. 207 00:11:07,700 --> 00:11:08,420 Here we go. 208 00:11:08,420 --> 00:11:10,850 Can I assign a value of type double to type float. 209 00:11:10,850 --> 00:11:13,130 So clearly this is a double. 210 00:11:13,130 --> 00:11:14,410 And clearly this is a float. 211 00:11:14,510 --> 00:11:18,320 So the point I was trying to make is by default it always chooses a double when you use the decimal 212 00:11:18,320 --> 00:11:19,100 points. 213 00:11:19,190 --> 00:11:23,150 And so when you're creating your apps you're only going to really ever use and doubles for the most 214 00:11:23,150 --> 00:11:26,420 part when you're working with numbers which is really cool. 215 00:11:26,780 --> 00:11:35,330 And I encourage you to actually read a whole lot more in this swift book about wherever it went about 216 00:11:35,630 --> 00:11:40,520 all these different things because they has incredibly valuable information incredibly valuable and 217 00:11:40,520 --> 00:11:46,760 it's actually Britain written with the proper keywords because sometimes you may hear an instructor 218 00:11:46,760 --> 00:11:50,360 or somebody talking about programming in general they're not using the right terms or summarizing it 219 00:11:50,360 --> 00:11:54,740 Swift actually in those books they actually use the right keywords and they teach what's going on under 220 00:11:54,740 --> 00:12:00,890 the hood and a lot of cases so those numbers right and you can do a lot of things with numbers. 221 00:12:00,890 --> 00:12:04,060 And we talked in the earlier video about operators. 222 00:12:04,600 --> 00:12:12,010 You're going to use what's called a rith take mad rith math. 223 00:12:12,410 --> 00:12:13,230 Oh my gosh. 224 00:12:13,280 --> 00:12:15,830 I'm sorry I just. 225 00:12:15,830 --> 00:12:18,890 Arithmetic arithmetic. 226 00:12:18,890 --> 00:12:20,600 All right. 227 00:12:20,600 --> 00:12:26,010 Rith metric arithmetic operators. 228 00:12:27,640 --> 00:12:31,400 If you're new to the class and you're wondering like why does he why does he leave some of the stuff 229 00:12:31,400 --> 00:12:34,800 in here like why do we make mistakes and things like that. 230 00:12:34,910 --> 00:12:37,420 And what happened was in the beginning I didn't always do that. 231 00:12:37,430 --> 00:12:40,300 I kind of cleaned up the code and made it look perfect. 232 00:12:40,290 --> 00:12:43,360 Boston's real like you're doing it so perfectly. 233 00:12:43,490 --> 00:12:44,750 You're just so amazing. 234 00:12:44,810 --> 00:12:47,870 I'm never going to be a programmer because you can't do it perfectly. 235 00:12:47,910 --> 00:12:51,240 And I was it guys and gals I'm not doing it perfectly. 236 00:12:51,290 --> 00:12:52,160 This is all edited. 237 00:12:52,160 --> 00:12:55,940 So I started making videos that were real like how programmers really solve problems. 238 00:12:55,970 --> 00:12:58,050 And then everyone's like I can do this. 239 00:12:58,130 --> 00:12:59,700 Mark prizes he's not a robot. 240 00:12:59,720 --> 00:13:02,040 He's a real person who has to figure things out and use his brain. 241 00:13:02,060 --> 00:13:03,080 And that's why we do these things. 242 00:13:03,080 --> 00:13:08,030 That's why these videos are so informal because I pretend that you're sitting here right next to me 243 00:13:08,030 --> 00:13:11,410 in the class so I can actually teach and convey a message to you. 244 00:13:11,420 --> 00:13:13,850 So again if you're new to all this this is how we do it. 245 00:13:13,850 --> 00:13:16,730 All right dev slopes and it's exciting and people love it. 246 00:13:16,730 --> 00:13:20,210 If you hate it I'm sorry I just love it. 247 00:13:20,210 --> 00:13:25,070 OK so arithmetic operators you know and this is just like in math and in high school right or grade 248 00:13:25,070 --> 00:13:25,930 school even right. 249 00:13:25,960 --> 00:13:33,220 You know you get a plus minus divide multiplication and things like that. 250 00:13:33,260 --> 00:13:37,750 And so you can actually you can actually play around with numbers which is kind of cool. 251 00:13:37,750 --> 00:13:45,440 One of my favorite ones is like doing the area of a shape or a rectangle so bar area equals and let's 252 00:13:45,440 --> 00:13:49,240 say lengths of 15 times with 20. 253 00:13:49,270 --> 00:13:50,070 OK. 254 00:13:50,090 --> 00:13:57,430 And we just did multiplication 315 times 20 which is really cool and we can do addition as well. 255 00:13:57,450 --> 00:14:09,220 Var sum equals five plus six bar diff for difference equals 10 minus three 32 10 minus 3. 256 00:14:09,470 --> 00:14:12,990 And so we're doing different operations here which is really cool. 257 00:14:13,070 --> 00:14:14,670 What about division committee division. 258 00:14:14,700 --> 00:14:28,420 Well yes we can we can say let's say 12 divided by groups some division 12 divided by three is four. 259 00:14:28,880 --> 00:14:31,150 But there's one more thing I want to show you. 260 00:14:31,160 --> 00:14:32,950 OK. 261 00:14:33,320 --> 00:14:38,900 What if you said bar divide and we said what is 12 divided by five. 262 00:14:40,710 --> 00:14:43,190 Do you think it's going to be groups. 263 00:14:43,230 --> 00:14:46,540 One equals 12 divided by five. 264 00:14:46,540 --> 00:14:49,360 And again these are just container names for giving them OK. 265 00:14:49,710 --> 00:14:53,900 So wait a minute 12 divided by five is not two words the remainder. 266 00:14:53,900 --> 00:15:00,240 There's got to be a remainder well in swift and pretty much every other programming language division 267 00:15:00,390 --> 00:15:03,400 or the arithmetic operator for division. 268 00:15:03,480 --> 00:15:11,820 This backslash here is only going to do the division and only give you how many times it goes into a 269 00:15:11,820 --> 00:15:12,190 number. 270 00:15:12,210 --> 00:15:14,620 The remainder actually is not going to be provided to you. 271 00:15:14,640 --> 00:15:21,570 So to get the remainder you actually have to use what's called the remainder operator or modulo or modulus. 272 00:15:21,570 --> 00:15:24,120 I've heard people say all kinds of things. 273 00:15:24,280 --> 00:15:29,310 Call it the modulo operators commonly used or the remainder operator that's what Swift calls the remainder 274 00:15:29,310 --> 00:15:30,260 operator. 275 00:15:30,300 --> 00:15:36,590 So the remainder operator is this equals 12 percent sign 5. 276 00:15:36,830 --> 00:15:37,620 OK. 277 00:15:37,920 --> 00:15:40,430 So which is two. 278 00:15:40,440 --> 00:15:44,780 There's two of a remainder OK right so five goes in the 12 two times with the remainder of two. 279 00:15:44,780 --> 00:15:50,650 Let's in fact let's do 13 just to show you that these are different numbers here OK. 280 00:15:51,080 --> 00:15:56,010 So so I wanted to show the full problem OK I could do something like this. 281 00:15:56,010 --> 00:15:59,880 Var result equals. 282 00:15:59,910 --> 00:16:00,860 This is going to be a string right. 283 00:16:00,870 --> 00:16:09,510 So the result of 13 divided by five is OK. 284 00:16:10,230 --> 00:16:13,650 We can use string interpolation here. 285 00:16:13,730 --> 00:16:25,430 Now OK to insert a variable in and we can say Div 1 and I will say dot for the decimal right with the 286 00:16:25,430 --> 00:16:28,500 remainder of. 287 00:16:29,100 --> 00:16:31,550 Not really the dots not really appropriate. 288 00:16:31,710 --> 00:16:41,470 Five is with a remainder of origo and then we'll put in the remainder. 289 00:16:42,030 --> 00:16:48,620 So the result of and divided by five is to with a remainder of three. 290 00:16:48,860 --> 00:16:49,400 OK. 291 00:16:49,650 --> 00:16:51,510 And don't worry if you don't understand all this just yet. 292 00:16:51,510 --> 00:16:53,610 I'm just inserting variables into my string. 293 00:16:53,610 --> 00:16:55,470 Here's the print out to the screen. 294 00:16:55,470 --> 00:16:59,190 So what happens with the remainder operator is it is going to do the division. 295 00:16:59,310 --> 00:17:02,250 But instead of returning the first number it's going returned the remainder. 296 00:17:02,250 --> 00:17:11,140 If there is a remainder and this is a great way to determine what numbers are even or odd even numbers 297 00:17:11,410 --> 00:17:16,930 will have no remainder right so if I wanted to know if number was even or Onslow say bar random number 298 00:17:17,350 --> 00:17:19,090 equals 13. 299 00:17:19,090 --> 00:17:25,750 So we can say if a random number modulo two equals zero. 300 00:17:25,750 --> 00:17:29,880 So the double equal sign is this something is something true or false you know. 301 00:17:29,920 --> 00:17:32,570 Or is this equal to that it's going to give you a boolean value. 302 00:17:32,650 --> 00:17:37,860 So if random number modulo or remainder operator two equals zero. 303 00:17:38,130 --> 00:17:40,480 OK you know we'll print. 304 00:17:40,570 --> 00:17:43,280 This is an even number. 305 00:17:43,900 --> 00:17:45,250 All right. 306 00:17:45,250 --> 00:17:46,740 Else. 307 00:17:46,860 --> 00:17:50,860 Print this is an odd number. 308 00:17:51,660 --> 00:17:52,470 OK. 309 00:17:52,890 --> 00:17:54,180 And so look it's printing up. 310 00:17:54,180 --> 00:17:57,550 This is an odd number but what if we turn this to 12. 311 00:17:57,610 --> 00:17:58,120 OK. 312 00:17:58,210 --> 00:17:59,320 So this is an even number. 313 00:17:59,320 --> 00:18:03,700 So this is something that is very commonly used to determine whether numbers are even or odd. 314 00:18:03,700 --> 00:18:04,570 Is this remainder. 315 00:18:04,570 --> 00:18:05,320 Operator. 316 00:18:05,440 --> 00:18:07,460 So you've done some basic arithmetic. 317 00:18:07,480 --> 00:18:11,400 We've talked about different types here like and double and low. 318 00:18:11,440 --> 00:18:15,300 You can use negative numbers you can use positive numbers. 319 00:18:15,430 --> 00:18:17,270 You can do all kinds of fun things. 320 00:18:17,270 --> 00:18:18,370 All right. 321 00:18:18,640 --> 00:18:22,510 And by the way this right here this is a very operator. 322 00:18:22,510 --> 00:18:25,220 Kind of like what we've talked about in the past. 323 00:18:25,360 --> 00:18:28,580 It's operating on one target here making a negative number here. 324 00:18:28,650 --> 00:18:32,610 Just so you know we'll well tip and trick right there. 325 00:18:32,900 --> 00:18:37,930 So don't worry too much about the NL so if you don't understand that just yet or the string into position 326 00:18:37,930 --> 00:18:42,580 that we used here the point of this lesson is to talk about numbers you can do math operations and of 327 00:18:42,580 --> 00:18:48,820 course order of operations are all followed in swift as well as most other programming languages so 328 00:18:49,140 --> 00:18:51,350 I can save our results. 329 00:18:51,370 --> 00:18:54,150 Two equals let's say 15 times. 330 00:18:54,310 --> 00:18:58,620 Five plus seven divided by three. 331 00:18:58,810 --> 00:18:59,120 All right. 332 00:18:59,170 --> 00:19:06,250 And if I want a five and seven to be done first and then I wanted the result of this to be done next 333 00:19:08,050 --> 00:19:08,860 I could do something like that. 334 00:19:08,860 --> 00:19:16,090 So just like you do in math like in high school the order of operations you know still applies the same 335 00:19:16,090 --> 00:19:18,970 that you would do in math in high school and you can use parentheses just like you would do in high 336 00:19:18,970 --> 00:19:23,130 school math to get the results that you are looking for. 337 00:19:23,140 --> 00:19:24,810 And again this is very foundational. 338 00:19:24,810 --> 00:19:30,130 Every app you've ever used uses math like this when you're swiping your card at a bank and it wants 339 00:19:30,130 --> 00:19:35,160 to deduct money it's got to use math to take money out of your bank account things like that. 340 00:19:35,230 --> 00:19:40,960 So you have now you as a basic foundational thing that you can use the rest of your life as a programmer 341 00:19:41,080 --> 00:19:43,250 and you never know that you'll ever build. 342 00:19:43,700 --> 00:19:45,590 So that's it numbers. 343 00:19:45,670 --> 00:19:48,440 Mark Price heads up slopes dot com. 344 00:19:48,460 --> 00:19:48,950 See you next.