WEBVTT 1 00:00:00.080 --> 00:00:02.759 Welcome to the dep dive. We're jumping straight into C 2 00:00:02.960 --> 00:00:04.759 Sharp twelve and dot Net eight today. 3 00:00:04.960 --> 00:00:06.679 Yeah, a real powerhouse duo. 4 00:00:06.679 --> 00:00:10.679 Definitely for building modern apps that well run pretty much anywhere. 5 00:00:10.880 --> 00:00:14.000 Our mission here is to kind of extract the essentials 6 00:00:14.039 --> 00:00:16.079 you need to navigate this stuff exactly. 7 00:00:16.399 --> 00:00:19.120 We're drawing from a pretty comprehensive resource on C Shark 8 00:00:19.120 --> 00:00:20.000 twelve and dot eight. 9 00:00:20.160 --> 00:00:23.600 Consider this your shortcut right setting up your dev playground, 10 00:00:23.679 --> 00:00:25.399 getting the Sea Shark basics. 11 00:00:25.039 --> 00:00:29.800 And exploring those core programming ideas all within this latest 12 00:00:29.800 --> 00:00:30.559 dot net evolution. 13 00:00:30.760 --> 00:00:34.079 Okay, let's unpack it. First things first, getting set up, 14 00:00:34.320 --> 00:00:35.719 choosing your environment right. 15 00:00:36.000 --> 00:00:39.399 The big two are Visual Studio twenty twenty two and Visual. 16 00:00:39.119 --> 00:00:42.880 Studio Code Yeah vs. Twenty twenty two, hugely popular with 17 00:00:42.920 --> 00:00:46.039 pro dot net devs, especially if you're mainly on Windows. 18 00:00:46.079 --> 00:00:48.200 It's that full ide experience right out of the. 19 00:00:48.119 --> 00:00:50.479 Box exactly guides you through set up you know, Sea 20 00:00:50.520 --> 00:00:54.119 Shark settings, choosing your theme, which is surprisingly important. 21 00:00:54.280 --> 00:00:55.960 Oh yeah, staring at it all day, you want it 22 00:00:56.000 --> 00:00:56.960 to look right. Uh. 23 00:00:57.240 --> 00:01:00.640 True, It's packed with features, so if you're deep Windows 24 00:01:00.840 --> 00:01:03.280 want that all in one feel. Vs. Twenty twenty two 25 00:01:03.359 --> 00:01:04.480 is probably your best. 26 00:01:04.280 --> 00:01:07.200 Bet, but then you've got Visual Studio Code the contrast. Yeah, 27 00:01:07.239 --> 00:01:12.760 it's big selling point is flexibility runs everywhere Windows, Mac, Linux, Yeah, 28 00:01:13.439 --> 00:01:17.239 even arm chips like Apple Silicon or Raspberry Pie. 29 00:01:17.280 --> 00:01:19.760 Super lightweight design too, right, And for. 30 00:01:19.760 --> 00:01:23.000 Dot network in vs code, the c Shark DevKit extension 31 00:01:23.239 --> 00:01:24.799 is well essential. 32 00:01:24.959 --> 00:01:27.159 Ah yeah, tell us about that. 33 00:01:27.280 --> 00:01:30.480 It brings in the features you need for like managing 34 00:01:30.519 --> 00:01:34.159 solutions with multiple projects. Really turns vs code into a 35 00:01:34.200 --> 00:01:35.400 proper dot net environment. 36 00:01:35.519 --> 00:01:38.400 So if you valued that cross platform agility and maybe 37 00:01:38.480 --> 00:01:40.159 work across different ocs. 38 00:01:39.879 --> 00:01:41.879 Or you just prefer a more modular, bill it yourself 39 00:01:41.959 --> 00:01:42.280 kind of. 40 00:01:42.359 --> 00:01:46.040 Editor, vs code with the DevKit is a strong contender totally. 41 00:01:46.480 --> 00:01:48.959 They even have that insider's version if you like living 42 00:01:49.040 --> 00:01:50.519 on the edge getting new features early. 43 00:01:50.680 --> 00:01:53.920 Okay, So organizing projects this idea of a solution. 44 00:01:53.760 --> 00:01:56.319 Yeah, that's key in both Visual Studio and vs code 45 00:01:56.319 --> 00:01:56.959 with the DevKit. 46 00:01:57.120 --> 00:01:59.680 Think of it like a binder, right, holding all your 47 00:01:59.680 --> 00:02:01.239 related projects together. 48 00:02:01.120 --> 00:02:04.760 Exactly your website code, maybe a class library, a console app. 49 00:02:05.319 --> 00:02:07.879 The solution file groups them. Let's the tools manage them 50 00:02:07.879 --> 00:02:08.560 as one unit. 51 00:02:08.719 --> 00:02:11.879 Our source mentions a chapter one solution holding a Hello 52 00:02:11.960 --> 00:02:13.159 CS project. 53 00:02:12.879 --> 00:02:16.360 Classic example, and that ties into the dot Net SDK, 54 00:02:16.639 --> 00:02:17.639 the Software. 55 00:02:17.280 --> 00:02:20.680 Development kit, which gives you the command line interface the CLI. 56 00:02:20.719 --> 00:02:24.000 Right fundamental for creating and managing projects. No matter which 57 00:02:24.159 --> 00:02:24.919 editor you use. 58 00:02:25.120 --> 00:02:26.639 You can use the CLI to spin up a new 59 00:02:26.639 --> 00:02:28.159 console app, for instance, yep. 60 00:02:28.000 --> 00:02:31.000 And it generates those basic files, the dot c Proja 61 00:02:31.080 --> 00:02:32.800 project file program. 62 00:02:32.400 --> 00:02:34.879 Dot cs and those bin and obj folders you see 63 00:02:34.919 --> 00:02:35.919 pop up, and. 64 00:02:35.879 --> 00:02:39.159 The c sharp DevKit in vs code just picks up 65 00:02:39.159 --> 00:02:40.840 those solution files and knows what to do. 66 00:02:40.919 --> 00:02:43.319 So the CLI is kind of the bedrock. Interacting with 67 00:02:43.360 --> 00:02:44.039 the core. 68 00:02:44.000 --> 00:02:48.360 Tools absolutely and understanding solutions is vital as your apps 69 00:02:48.360 --> 00:02:50.960 get bigger, more complex, maybe split into different parts. 70 00:02:51.039 --> 00:02:54.520 Okay, let's actually build something super basic, a console app. 71 00:02:54.639 --> 00:02:55.639 Walk is through it right. 72 00:02:55.759 --> 00:02:58.879 You typically use a template, right, the c shark console 73 00:02:58.960 --> 00:03:00.280 app template yep. 74 00:03:00.360 --> 00:03:01.479 Give it a project name. 75 00:03:01.400 --> 00:03:05.520 Like hellocs, choose where to save it maybe CR twelve, dot. 76 00:03:05.520 --> 00:03:08.199 Net eight, and name the solution like chapter one. 77 00:03:08.439 --> 00:03:13.319 And there's that interesting option mentioned about disabling native aot publish. 78 00:03:13.400 --> 00:03:16.599 Yah ahead of time compilation piles straight to machine code. 79 00:03:16.479 --> 00:03:19.919 Faster startup, smaller size in some cases, but we'll park 80 00:03:19.960 --> 00:03:21.400 that for now. It's covered later right. 81 00:03:21.479 --> 00:03:23.199 So once you create the project. 82 00:03:22.840 --> 00:03:26.000 You get this program dot cs file and it's usually 83 00:03:26.080 --> 00:03:28.039 super simple at first. 84 00:03:27.919 --> 00:03:30.199 Often just a comment and maybe one line of code 85 00:03:30.400 --> 00:03:31.759 like console right line. 86 00:03:32.000 --> 00:03:35.000 It's deliberately minimal, a clean slate. 87 00:03:34.919 --> 00:03:38.280 And a good place to start poking around, like finding 88 00:03:38.360 --> 00:03:41.280 out the name space of that default program class. 89 00:03:41.319 --> 00:03:44.280 Oh right, the source had that snippet type of program 90 00:03:44.280 --> 00:03:45.599 dot namespace. 91 00:03:45.240 --> 00:03:50.759 String nameycal type of program dot namespace none, console right 92 00:03:50.840 --> 00:03:52.759 line namespace dot e something like that. 93 00:03:52.840 --> 00:03:54.520 Just a handy way to see how your code's. 94 00:03:54.280 --> 00:03:56.960 Organized, definitely, and you can take that further, get environment 95 00:03:57.000 --> 00:03:59.919 info like the current director jarn director yeah, or the OS. 96 00:03:59.759 --> 00:04:03.680 Version environment do OS version version string in that name space. 97 00:04:03.719 --> 00:04:07.039 Again, just useful for seeing where your code is actually running. 98 00:04:07.639 --> 00:04:08.800 Good for debugging, like. 99 00:04:08.759 --> 00:04:10.400 A quick health check of the environment. 100 00:04:10.560 --> 00:04:15.560 Exactly what OSM I on? Where are my files? Useful stuff. 101 00:04:15.840 --> 00:04:19.680 One last dev environment tip. They mentioned inline hints or 102 00:04:19.680 --> 00:04:20.399 inlay hints. 103 00:04:20.480 --> 00:04:23.199 Oh, those are great little reminders right in the code. 104 00:04:23.360 --> 00:04:26.040 Yeah, they show the parameter names when you're calling a method, so. 105 00:04:25.959 --> 00:04:28.399 You don't have to keep jumping back to the definition exactly. 106 00:04:28.519 --> 00:04:30.319 Saves a lot of cognitive load. You can turn them 107 00:04:30.319 --> 00:04:32.639 on in VS twenty twenty two's options. 108 00:04:32.240 --> 00:04:37.639 Tools, Options text Editor, c shap advanced inline hints somewhere 109 00:04:37.680 --> 00:04:38.160 in there. 110 00:04:38.000 --> 00:04:40.759 And in VS code you just search settings for inline hints. 111 00:04:40.879 --> 00:04:43.519 Small feature, big impact on readability. 112 00:04:43.519 --> 00:04:49.399 Sometimes totally agree. Okay, moving on C sharp fundamentals, grammar, vocabulary, 113 00:04:50.000 --> 00:04:50.879 the building blocks. 114 00:04:51.079 --> 00:04:53.279 Right, So the C shark compiler is called Roslin. 115 00:04:53.439 --> 00:04:56.519 Think of Roslyn as the translator takes your C sharp. 116 00:04:56.360 --> 00:04:59.959 And turns it into intermediate language. 117 00:05:00.600 --> 00:05:03.560 Which gets stored in assemblies of those DLL or ex 118 00:05:03.720 --> 00:05:05.439 files YEP package code. 119 00:05:05.839 --> 00:05:08.800 Then the dot Net run times Virtual Machine core CLR 120 00:05:08.920 --> 00:05:11.519 that's the engine kinda it uses it just in time, 121 00:05:11.639 --> 00:05:13.959 or JIT compiler. 122 00:05:13.680 --> 00:05:15.839 Which translates that IL into. 123 00:05:15.879 --> 00:05:19.439 Native CPU instructions. The stuff your actual process or understands 124 00:05:19.560 --> 00:05:20.439 happens at runtime. 125 00:05:20.639 --> 00:05:23.839 So C sharp to IL with Roslin, then IL to 126 00:05:23.920 --> 00:05:26.279 native code with the JIT and core CLR. 127 00:05:26.399 --> 00:05:28.800 You got it. It's a neat separation. Let's see sharp 128 00:05:28.879 --> 00:05:32.360 evolve kind of independently from the runtime details helps with 129 00:05:32.399 --> 00:05:34.000 cross platform two makes sense. 130 00:05:34.480 --> 00:05:38.959 Now, C sharp grammar, we're talking statements. 131 00:05:38.519 --> 00:05:44.279 Blocks, code inside curly braces and comments crucial for explaining things. 132 00:05:44.399 --> 00:05:47.360 But the advice is, yeah, the implicitly or globally imported. 133 00:05:47.639 --> 00:05:51.639 Saves you typing using system or using system dot collections 134 00:05:51.839 --> 00:05:53.199 generic all the time. 135 00:05:53.240 --> 00:05:54.519 Where does that info live? 136 00:05:54.639 --> 00:05:56.680 It's generated in that of data bug Net eight point 137 00:05:56.720 --> 00:05:59.439 zero folder, usually in a dot global usings dot g 138 00:05:59.519 --> 00:06:00.959 dot c s file. We're similar. 139 00:06:01.079 --> 00:06:04.560 So for basic console app Microsoft dot net SDK, you 140 00:06:04.600 --> 00:06:07.839 get systemsystem, dot io, system dot. 141 00:06:07.639 --> 00:06:10.600 Link common stuff, and if it's a web project Microsoft 142 00:06:10.639 --> 00:06:14.079 dot net sdk web you get more like asthmiccore stuff 143 00:06:14.319 --> 00:06:15.639 net dot HGDP Jason. 144 00:06:16.120 --> 00:06:19.079 It's just about reducing boilerplate, making common types easy to. 145 00:06:19.040 --> 00:06:21.560 Access precisely, less clutter, focus on your. 146 00:06:21.480 --> 00:06:24.480 Logic, and finally literals simple concepts. 147 00:06:24.560 --> 00:06:26.879 Yeah, just the way you write fixed values directly in 148 00:06:26.920 --> 00:06:28.120 your code, like the number. 149 00:06:27.920 --> 00:06:30.959 One, two, three, or the text hello or true. 150 00:06:30.720 --> 00:06:33.759 False, exactly the raw value itself written in the source. 151 00:06:33.839 --> 00:06:36.199 All right, let's talk about scoring different kinds of data, 152 00:06:36.360 --> 00:06:37.240 starting with texts. 153 00:06:37.279 --> 00:06:40.399 Okay, so the basic unit is char for a single character. 154 00:06:40.480 --> 00:06:42.040 But there's a catch with unicode. 155 00:06:42.199 --> 00:06:46.199 Uh huh. Some characters, especially emojis, are less common. Symbols 156 00:06:46.519 --> 00:06:49.600 might actually need two char values called surrogate. 157 00:06:49.199 --> 00:06:53.480 Pairs, so one visual character doesn't always equal one char variable. 158 00:06:53.439 --> 00:06:55.720 Exactly something to be aware of if you're doing low 159 00:06:55.800 --> 00:06:59.240 level text manipulation. Got to handle Unicode properly. 160 00:06:59.439 --> 00:06:59.920 Good point. 161 00:07:00.079 --> 00:07:03.240 What about numbers, lots of options. For whole numbers, you've 162 00:07:03.279 --> 00:07:07.480 got integers, int is common handles positive and negative, int 163 00:07:07.600 --> 00:07:08.800 is unsigned only. 164 00:07:08.560 --> 00:07:11.839 Positive, and for numbers with decimal points. 165 00:07:11.519 --> 00:07:14.720 Floating point types float, you need an F suffix like 166 00:07:14.759 --> 00:07:17.439 three point one forty f and double, which is the 167 00:07:17.439 --> 00:07:19.519 default if you just right say three point one. 168 00:07:19.560 --> 00:07:22.079 Four, and then there's decimal for high precision. 169 00:07:21.800 --> 00:07:25.319 Right crucial for financial stuff yeh, where tiny rounding errors 170 00:07:25.360 --> 00:07:28.480 are bad news. Use an M suffix like twelve point 171 00:07:28.560 --> 00:07:29.160 nine to nine ter. 172 00:07:29.519 --> 00:07:32.360 So the difference is memory, use range of values and 173 00:07:32.399 --> 00:07:33.639 that precision. 174 00:07:33.199 --> 00:07:36.759 Aspect spot on integers for whole numbers, floats doubles for 175 00:07:36.800 --> 00:07:39.839 general fractional numbers, decimal for exact decimal. 176 00:07:39.519 --> 00:07:41.759 Representation, and we can check their size yep. 177 00:07:41.959 --> 00:07:44.399 Using the size operator tells you how many. 178 00:07:44.199 --> 00:07:46.319 Bites they take up, and find their limit. 179 00:07:46.160 --> 00:07:48.519 Mind value and max value properties on the types themselves, 180 00:07:48.560 --> 00:07:51.079 like into dot minvalue, double dot max value. 181 00:07:51.160 --> 00:07:53.959 The source had that classic point one plus point two. 182 00:07:53.959 --> 00:07:57.439 Example, right, yeah, showing how double might give you point 183 00:07:57.439 --> 00:08:00.360 three zero zero zero zero zero zero zero zero zero 184 00:08:00.519 --> 00:08:03.959 zero four. Well, decimal gives you exactly point three. It's 185 00:08:04.000 --> 00:08:05.680 because of how they store the numbers internally. 186 00:08:05.759 --> 00:08:09.040 Fascinating. That precision difference is huge sometimes. 187 00:08:08.560 --> 00:08:11.120 It really can be. Understanding the tradeoffs is important. 188 00:08:11.120 --> 00:08:14.439 What about those huge integer types in one two eight. 189 00:08:14.480 --> 00:08:16.399 H yeah, system dot in one two eight and U 190 00:08:16.639 --> 00:08:19.759 twenty two eight added in dot net seven massive sixteen 191 00:08:19.800 --> 00:08:20.879 byte integers. 192 00:08:20.560 --> 00:08:22.319 But using size klanumum is. 193 00:08:22.279 --> 00:08:26.360 Tricky, requires unsafe code and a compiler flag. Definitely an 194 00:08:26.399 --> 00:08:30.680 advanced feature for specialized needs like really big numbers and calculations. 195 00:08:30.800 --> 00:08:33.519 Got it back to basics. String for text. 196 00:08:33.279 --> 00:08:37.399 YEP sequences of characters pretty straightforward, has a length property. 197 00:08:37.080 --> 00:08:39.399 And they're immutable. Right. You can't change a string once 198 00:08:39.399 --> 00:08:40.000 it's created. 199 00:08:40.080 --> 00:08:43.360 Correct. Operations that look like they modify a string actually 200 00:08:43.600 --> 00:08:46.639 create a new string. Important for performance if you're doing 201 00:08:46.720 --> 00:08:47.720 tons of manipulation. 202 00:08:48.000 --> 00:08:50.240 Okay, now var the keyword var? 203 00:08:50.399 --> 00:08:52.120 Oh yeah, tech difference superhandy. 204 00:08:52.159 --> 00:08:53.960 What's the compiler figure out the type exactly? 205 00:08:54.039 --> 00:08:56.679 Instead of string message hi, you can just write var 206 00:08:56.759 --> 00:08:58.159 message hi and. 207 00:08:58.080 --> 00:09:00.799 The editor usually shows you what type it an YEP. 208 00:09:00.799 --> 00:09:02.840 Hover over var and it'll tell you a string. 209 00:09:03.039 --> 00:09:05.159 Makes code shorter, but maybe less explicit. 210 00:09:05.240 --> 00:09:08.639 Sometimes it's a balance. Great for complex tykes where spelling 211 00:09:08.639 --> 00:09:12.240 it out is noisy, but sometimes being explicit makes things clearer. 212 00:09:12.720 --> 00:09:16.000 Use it wisely, right, Okay, back to console apps. 213 00:09:15.720 --> 00:09:18.759 For a sec text based run from the command line. 214 00:09:18.879 --> 00:09:22.080 Good for scripts, simple tools, learning. 215 00:09:22.080 --> 00:09:25.840 And importantly they can take arguments from the command line. 216 00:09:25.919 --> 00:09:28.519 We'll get to that first. Making the output look nice. 217 00:09:28.720 --> 00:09:30.720 String formatting several ways to do it. 218 00:09:30.960 --> 00:09:33.840 The classic placeholders console right line. 219 00:09:33.799 --> 00:09:37.000 Name, name, age aw that style yep. 220 00:09:37.159 --> 00:09:39.840 Or you can use named arguments for clarity, especially with 221 00:09:39.919 --> 00:09:41.960 multiple parameters of the same type. 222 00:09:41.799 --> 00:09:45.759 Like console dot right line arg one first R one 223 00:09:46.000 --> 00:09:46.799 second right. 224 00:09:47.360 --> 00:09:49.720 The source also mentioned boxing warnings. 225 00:09:50.120 --> 00:09:53.240 Yeah said it's more unity thing less critical for general 226 00:09:53.360 --> 00:09:54.559 dot net apps covered here. 227 00:09:54.679 --> 00:09:55.879 Okay, big one though. 228 00:09:56.039 --> 00:09:56.440 Yeah. 229 00:09:56.480 --> 00:09:58.159 Culture's impact on formatting. 230 00:09:58.279 --> 00:10:03.000 Oh yeah, numbers, dates, currency, They look different depending on 231 00:10:03.039 --> 00:10:04.320 region settings. 232 00:10:04.320 --> 00:10:07.600 Five versus doc A, comma versus dot for one thousand separators. 233 00:10:07.840 --> 00:10:08.840 But you can control it. 234 00:10:09.000 --> 00:10:14.080 Yeah, definitely specify a culture like culture info invariant culture 235 00:10:14.159 --> 00:10:17.039 for consistent machine readable formats, or. 236 00:10:17.120 --> 00:10:21.080 Use custom format strings like zero for zero, placeholder hashtag 237 00:10:21.080 --> 00:10:22.240 for digit exactly. 238 00:10:22.639 --> 00:10:25.600 Table two point eight in the source has details lots 239 00:10:25.639 --> 00:10:26.440 of control. 240 00:10:26.080 --> 00:10:29.240 There, and the easiest way often is string interpolation. The 241 00:10:29.279 --> 00:10:31.080 dollar sign syntax. 242 00:10:30.759 --> 00:10:34.720 Variable yep usually much cleaner. Console right line. 243 00:10:34.720 --> 00:10:40.000 H reads nicely okay, nullable reference types nrts. Big change 244 00:10:40.000 --> 00:10:41.639 in modern C sharp. 245 00:10:41.480 --> 00:10:44.799 Huge designed to tackle those dreaded noull reference exception errors. 246 00:10:45.120 --> 00:10:47.519 By adding a question mark spring right. 247 00:10:47.919 --> 00:10:50.799 It tells a compiler this variable might be null, and. 248 00:10:50.720 --> 00:10:52.679 The compiler then warns you if you try to use 249 00:10:52.679 --> 00:10:54.240 it without checking exactly. 250 00:10:54.720 --> 00:10:57.840 It performs static analysis to find potential null issues before 251 00:10:57.879 --> 00:11:00.399 you run. The code makes things much safer. 252 00:11:00.039 --> 00:11:01.679 But you still have to handle the null case right. 253 00:11:01.720 --> 00:11:03.600 The knot is a warning system precisely. 254 00:11:04.240 --> 00:11:06.639 It forces you to think about nulls, but you still 255 00:11:06.720 --> 00:11:10.679 need if my string null checks or similar patterns. It 256 00:11:10.679 --> 00:11:13.960 doesn't magically fixed nulls. It makes them explicit. Got it? 257 00:11:14.039 --> 00:11:16.039 Okay? Command line arguments? How do we get those? 258 00:11:16.240 --> 00:11:19.639 When you run your app like dot Net, run first arg, second. 259 00:11:19.480 --> 00:11:21.600 Arc Those first arg second arg pieces. 260 00:11:21.679 --> 00:11:24.200 They get passed into your main method as an array 261 00:11:24.200 --> 00:11:26.919 of strings, usually called arcs string arcs. 262 00:11:26.960 --> 00:11:29.399 So urg zero would be first RG, ARGs one would 263 00:11:29.399 --> 00:11:30.240 be second arc yep. 264 00:11:30.320 --> 00:11:32.039 You can move through the arg's array and use those 265 00:11:32.120 --> 00:11:34.919 values to change how your app behaves. Super useful for 266 00:11:34.960 --> 00:11:36.519 making tools flexible makes. 267 00:11:36.320 --> 00:11:41.519 Sense, and that platform specific example, setting cursor size. 268 00:11:41.320 --> 00:11:44.240 Right works on Windows throws an exception on MCLINICX A. 269 00:11:44.200 --> 00:11:47.080 Good reminder that even with cross platform dot net, the 270 00:11:47.240 --> 00:11:49.639 underlying OS still matters. 271 00:11:49.320 --> 00:11:53.240 Sometimes absolutely, and the solution often a tricatch block. 272 00:11:53.440 --> 00:11:55.840 Try to set the cursor size, catch the exception if 273 00:11:55.879 --> 00:11:57.840 it fails on Linux or Mac exactly. 274 00:11:58.240 --> 00:12:01.879 Graceful handling of platform difference. We'll dig more into trycatch soon. 275 00:12:02.039 --> 00:12:06.679 Perfect segue. Let's move into core programming concepts, starting with operators. 276 00:12:06.720 --> 00:12:10.799 Basic math, your bread butter plus AA for AD, subtract 277 00:12:10.919 --> 00:12:15.600 multiplied divide and per modulo the remainder after division ten 278 00:12:15.639 --> 00:12:16.639 percent three is one? 279 00:12:16.799 --> 00:12:20.480 Got it? Logical operators and for a ing for R 280 00:12:20.679 --> 00:12:22.600 and they have that short circuiting behavior. 281 00:12:22.720 --> 00:12:25.919 Yeah, that's important. With Andy in if the left side 282 00:12:25.919 --> 00:12:27.919 is false, it doesn't even look at the right. 283 00:12:27.799 --> 00:12:30.679 Side because the whole thing must be false anyway, right And. 284 00:12:30.639 --> 00:12:32.720 With Andy and if the left side is true, it 285 00:12:32.759 --> 00:12:35.000 skips the right side because the whole thing must be true. 286 00:12:35.080 --> 00:12:38.120 Good for performance avoids unnecessary. 287 00:12:37.519 --> 00:12:42.639 Work usually, but be careful if the right side expression 288 00:12:42.679 --> 00:12:45.080 has side effects you rely on happening. 289 00:12:45.600 --> 00:12:48.000 Like calling a function that's supposed to always log something 290 00:12:48.200 --> 00:12:49.639 it might get skipped exactly. 291 00:12:50.120 --> 00:12:53.320 Can lead to subtle bugs, something to be aware of, okay. 292 00:12:53.679 --> 00:12:55.399 Making decisions. 293 00:12:55.440 --> 00:12:58.879 Switch statements a way to handle multiple choices based on 294 00:12:58.919 --> 00:13:02.120 a single value, cleaner than lots of if l's ifs. 295 00:13:02.159 --> 00:13:05.559 Sometimes you have case labels for specific values, a default 296 00:13:05.559 --> 00:13:08.240 case for everything else, and C shark allows go to 297 00:13:08.279 --> 00:13:10.639 within a switch jump to other cases. 298 00:13:10.720 --> 00:13:14.159 It does. Yeah, use with caution, though can make code 299 00:13:14.200 --> 00:13:16.440 harder to follow if overused. 300 00:13:16.080 --> 00:13:18.759 Right and then There are switch expressions in newer C 301 00:13:18.960 --> 00:13:19.639 sharp versions. 302 00:13:19.679 --> 00:13:23.200 Yeah, C sharp eight onwards. More concise, often more powerful, 303 00:13:23.320 --> 00:13:24.799 especially with pattern matching. 304 00:13:25.000 --> 00:13:29.399 That example with animals was cool checking the type and properties. 305 00:13:28.799 --> 00:13:31.840 Cat four legged cat when four leggd cat legs equals. 306 00:13:31.480 --> 00:13:33.559 Four that kind of thing, or just matching the type 307 00:13:33.639 --> 00:13:37.879 cat cat or property pattern spider spider when Spider's poisonous. 308 00:13:37.440 --> 00:13:41.360 Handling null using the discard as a default, very expressive, 309 00:13:42.080 --> 00:13:44.559 often leads to cleaner code for complex conditions. 310 00:13:44.799 --> 00:13:47.000 Definitely looks more functional, more declarative. 311 00:13:47.039 --> 00:13:50.720 It leans that way, Yeah, okay. Storing collections a raise 312 00:13:51.200 --> 00:13:55.919 the basic fix size collection string names, new string three. 313 00:13:55.879 --> 00:13:59.440 Create space for three strings, access them with indices starting 314 00:13:59.480 --> 00:14:00.639 at zero always. 315 00:14:00.440 --> 00:14:04.320 Zero based name zero, names one, names two. 316 00:14:04.360 --> 00:14:06.600 And loop through them with a four loop and the 317 00:14:06.679 --> 00:14:08.000 link property. 318 00:14:08.120 --> 00:14:12.320 I names length iplus plus new names standard stuff. 319 00:14:12.360 --> 00:14:15.759 What about those inline arrays and c share twelve ah 320 00:14:16.159 --> 00:14:16.399 more of. 321 00:14:16.399 --> 00:14:19.399 An advanced behind the scenes performance thing for the runtime team. 322 00:14:19.440 --> 00:14:22.799 Mostly so not something you typically declare yourself in application code. 323 00:14:23.080 --> 00:14:26.559 Probably not directly no, but you might benefit from libraries 324 00:14:26.639 --> 00:14:28.600 using them under the hood. There's a link if you 325 00:14:28.600 --> 00:14:30.039 want the deep dive on those. 326 00:14:30.360 --> 00:14:32.399 Gotcha and formatting output again. 327 00:14:32.559 --> 00:14:35.759 Aligning column yeah, index alignment yeah, like zero zero twelve 328 00:14:35.840 --> 00:14:38.720 pads with spaces to align right in a twelve. 329 00:14:38.559 --> 00:14:41.679 Character call, and showing binary index ed format string. 330 00:14:41.639 --> 00:14:44.159 Like zero three four point b three two shows a 331 00:14:44.240 --> 00:14:49.039 number is thirty two bits. Binary representation potentially padded useful 332 00:14:49.039 --> 00:14:50.039 for low level inspection. 333 00:14:50.360 --> 00:14:54.759 Okay, getting data in parsing strings to numbers. 334 00:14:54.320 --> 00:14:58.080 Or dates, big parse, daytime dot parse common methods, but they. 335 00:14:58.000 --> 00:15:00.480 Can fail throw exceptions at the string. Isn't it right? 336 00:15:00.559 --> 00:15:04.759 Yep, format exception. That's why culture matters too, cultureinfo dot 337 00:15:04.759 --> 00:15:08.440 invariant culture to avoid nasty surprises with different date or 338 00:15:08.519 --> 00:15:09.879 number formats. 339 00:15:09.559 --> 00:15:11.720 So the safer way is tripars. 340 00:15:12.080 --> 00:15:15.679 Generally yes. In trpars input string out in a result, 341 00:15:16.080 --> 00:15:17.120 it returns true or. 342 00:15:17.080 --> 00:15:19.799 False, true if it worked, and the result variable gets. 343 00:15:19.639 --> 00:15:22.159 The value false if it failed, and result gets a 344 00:15:22.159 --> 00:15:25.039 default value like zero for end no exception thrown. 345 00:15:25.480 --> 00:15:28.799 Much cleaner for handling potentially bad user input avoids the 346 00:15:28.840 --> 00:15:31.360 overhead of exceptions for expected failures. 347 00:15:30.960 --> 00:15:33.559 Exactly use pars when you're sure the input is valid. 348 00:15:33.720 --> 00:15:35.000 Trypars when it might not be. 349 00:15:35.240 --> 00:15:38.679 And if parse does thrown exception or something else goes wrong. 350 00:15:39.039 --> 00:15:40.720 That's where tricatch finally comes in. 351 00:15:40.879 --> 00:15:43.120 Right wrap the risky code in try. 352 00:15:43.000 --> 00:15:46.559 Handle specific errors in catch format exception x or. 353 00:15:46.519 --> 00:15:49.799 More general errors in catch. Oh, I say, and use 354 00:15:49.840 --> 00:15:51.960 finally for cleanup. Code that always. 355 00:15:51.720 --> 00:15:55.399 Runs, always runs, whether an exception happen or not, whether 356 00:15:55.399 --> 00:15:58.879 it's caught or not. Good for releasing resources like closing files. 357 00:15:59.559 --> 00:16:00.919 Essential for robust code. 358 00:16:01.000 --> 00:16:03.639 Okay, integer overflow numbers getting too. 359 00:16:03.600 --> 00:16:07.840 Big Yeah by default se sharp injurer math is unchecked. 360 00:16:08.480 --> 00:16:12.000 If indemac's value plus one happens, it wraps around silently 361 00:16:12.080 --> 00:16:14.120 to int men value. 362 00:16:13.879 --> 00:16:15.799 Which can cause very weird bugs. 363 00:16:15.879 --> 00:16:18.440 Totally, so you can use the checked keyword. 364 00:16:18.120 --> 00:16:21.480 Either as a block yeah result large number one plus 365 00:16:21.600 --> 00:16:22.240 large numb. 366 00:16:22.039 --> 00:16:24.120 Two, or as compiler option for the whole project. 367 00:16:24.279 --> 00:16:27.559 And if overflow happens inside a checked context. 368 00:16:27.080 --> 00:16:30.200 It throws an overflow exception instead of wrapping silently makes 369 00:16:30.240 --> 00:16:31.080 the error obvious. 370 00:16:31.360 --> 00:16:34.960 There's a slight performance cost, but often worth it for correctness. 371 00:16:34.960 --> 00:16:38.759 Definitely something to consider, especially with financial or critical calculations. 372 00:16:39.080 --> 00:16:43.120 All right, getting near the end functions or methods in 373 00:16:43.200 --> 00:16:47.080 C sharp reusable blocks of code key for organization. The 374 00:16:47.120 --> 00:16:50.200 example was time stable took a required number. 375 00:16:50.080 --> 00:16:53.399 And an optional sized parameter with a default value void. 376 00:16:53.480 --> 00:16:55.720 Time stable INNT number in size. 377 00:16:55.559 --> 00:16:57.639 Is twelve, meaning you can call it with just the 378 00:16:57.720 --> 00:17:00.399 number time stable five and size default. 379 00:17:00.120 --> 00:17:03.720 To twelve, or provide both time stable five twenty. 380 00:17:03.440 --> 00:17:07.440 And using named arguments makes calls clearer. Time stable number 381 00:17:07.680 --> 00:17:09.440 five size twenty. 382 00:17:09.359 --> 00:17:13.079 Especially useful when there are multiple optional parameters or parameters 383 00:17:13.079 --> 00:17:16.839 of the same type. Improves readability quick terminology. 384 00:17:16.920 --> 00:17:19.160 Check parameter versus argument. 385 00:17:19.119 --> 00:17:21.720 Parameter is the variable in the function definition in number 386 00:17:21.720 --> 00:17:24.720 in size. Argument is the actual value passed in when 387 00:17:24.759 --> 00:17:26.119 you call the function five twenty. 388 00:17:26.200 --> 00:17:28.079 Got it and functions can return values too. 389 00:17:28.240 --> 00:17:32.119 Of course, the calculator tax example took an amount and reagencode. 390 00:17:31.880 --> 00:17:34.000 Used to switch expression based on the region. 391 00:17:33.799 --> 00:17:37.960 And return the calculated decimal tax value return calculated tax. 392 00:17:38.079 --> 00:17:40.519 Perfect for encapsulating a calculation. 393 00:17:40.079 --> 00:17:42.640 Or rule absolutely and documenting these functions. 394 00:17:42.920 --> 00:17:48.599 XML comments Yeah, those triple slash comments summary summary editors. 395 00:17:48.319 --> 00:17:50.200 Pick those up and show them as tooltips when you're 396 00:17:50.240 --> 00:17:51.200 calling the function. 397 00:17:51.279 --> 00:17:56.359 Explains what it does, parameters, return value. Huge help for maintainability, 398 00:17:56.640 --> 00:17:57.880 good practice definitely. 399 00:17:58.640 --> 00:18:02.920 Lastly, that decline larrative versus imperative style comparison. 400 00:18:02.480 --> 00:18:04.359 Using the Fibonacci sequence. 401 00:18:04.119 --> 00:18:08.279