WEBVTT 1 00:00:00.080 --> 00:00:02.080 Have you ever looked at some new tech, maybe a 2 00:00:02.080 --> 00:00:05.280 programming language, and just thought, Okay, I need to understand this, 3 00:00:05.480 --> 00:00:08.720 but where do I even begin with all the info 4 00:00:08.759 --> 00:00:12.359 out there. Well, today we're cutting right through the noise. 5 00:00:12.599 --> 00:00:15.679 We are, indeed, we're taking a deep dive into Cotland. 6 00:00:15.720 --> 00:00:18.559 That's the language that's been making some serious waves, you know, 7 00:00:18.960 --> 00:00:21.960 especially since Google really embraced it for Android development. 8 00:00:22.079 --> 00:00:24.640 Right, the Google announcement was huge, and you've given us 9 00:00:24.640 --> 00:00:27.199 a fantastic guide to work from for this deep dive, 10 00:00:27.480 --> 00:00:31.120 the Ultimate Beginner's Guide to learn Cotland Programming step by 11 00:00:31.120 --> 00:00:34.159 step from twenty twenty. So our mission today is basically 12 00:00:34.159 --> 00:00:37.320 to pull out the core ideas from that guide, explain 13 00:00:37.399 --> 00:00:41.719 what makes Cotland well tick, why developers seem. 14 00:00:41.560 --> 00:00:43.960 To really like it, exactly, why they call it a 15 00:00:44.000 --> 00:00:46.880 breath of fresh air. We'll unpack its key features. Yeah, 16 00:00:47.200 --> 00:00:49.560 see how it stacks up against languages people might know, 17 00:00:49.679 --> 00:00:52.920 like a Java or Skala, and we'll even touch on 18 00:00:52.960 --> 00:00:55.280 how it's actually being used out there in the real world. 19 00:00:55.359 --> 00:00:57.600 So what does this all mean for you the listener, 20 00:00:57.679 --> 00:01:00.280 whether you're maybe thinking about picking up a new skill 21 00:01:00.759 --> 00:01:03.079 or just want to understand the tech landscape A bit better, 22 00:01:03.399 --> 00:01:07.319 or maybe you're just curious. Let's unpack this. Okay, let's 23 00:01:07.359 --> 00:01:11.079 kick things out with the basics. What is Cotland fundamentally. 24 00:01:10.560 --> 00:01:13.280 Well, it's not brand brand new. The one point oh 25 00:01:13.319 --> 00:01:17.480 release was back in February twenty sixteen. Okay, but yeah, 26 00:01:17.519 --> 00:01:20.599 the guide calls it the new love child of the 27 00:01:20.719 --> 00:01:25.079 JVM developers world, which is quite a statement, it really is. 28 00:01:25.200 --> 00:01:27.200 Suggests it's more than just another option. 29 00:01:27.239 --> 00:01:30.879 Definitely, and that breath of fresh air comment keeps coming up. 30 00:01:31.000 --> 00:01:33.359 People see it as a really good upgrade, especially if 31 00:01:33.359 --> 00:01:36.079 you're coming from say, older Java versions. 32 00:01:36.159 --> 00:01:38.439 So let's dig into that comparison with Java. What makes 33 00:01:38.439 --> 00:01:40.760 Cotland different? Why is it seen as better? 34 00:01:41.000 --> 00:01:45.000 The guide highlights two main things. It's much safer and 35 00:01:45.040 --> 00:01:46.560 more concise than Java. 36 00:01:46.640 --> 00:01:48.719 Safer and more concise. How so, Well, it. 37 00:01:48.680 --> 00:01:52.959 Adds features that directly address things Java developers have, let's say, 38 00:01:53.120 --> 00:01:54.799 grown to dislike over the years. 39 00:01:54.879 --> 00:01:57.280 Okay, Like, what give us some examples. 40 00:01:57.319 --> 00:02:00.519 Big one null safety built right into the time system 41 00:02:00.519 --> 00:02:03.159 to help prevent those dreaded null pointer exceptions. 42 00:02:03.200 --> 00:02:05.200 Ah, the billion dollar mistake. 43 00:02:04.920 --> 00:02:08.199 Right exactly. Then you have things like extension functions, adding 44 00:02:08.240 --> 00:02:13.159 functionality to existing classes without needing to inherit super handy. Also, 45 00:02:13.479 --> 00:02:17.599 data classes these massively cut down on boilerplate code. 46 00:02:17.639 --> 00:02:21.400 Boilerplate yeah, like getters, setters equals. 47 00:02:20.919 --> 00:02:24.000 Hash code precisely that. Plus it has better support for 48 00:02:24.280 --> 00:02:29.719 functional programming, first class functions, really expressive lambdas and improvements 49 00:02:29.719 --> 00:02:33.319 and type inference, the type system generally, and even the 50 00:02:33.319 --> 00:02:35.120 collections library feels more modern. 51 00:02:35.240 --> 00:02:37.800 Okay, that data class point sounds really interesting. Can you 52 00:02:37.800 --> 00:02:39.879 make that a bit more tangible? Like? How bad is 53 00:02:39.919 --> 00:02:41.520 it in Java versus Cotlin? 54 00:02:41.680 --> 00:02:42.000 Sure? 55 00:02:42.080 --> 00:02:42.159 So? 56 00:02:42.360 --> 00:02:44.719 In Java, if you want a simple class to just 57 00:02:44.759 --> 00:02:47.039 hold some data what they call a pojo plain old 58 00:02:47.120 --> 00:02:50.560 Java object, you end up writing, honestly, dozens of lines. 59 00:02:50.639 --> 00:02:53.639 You need fields, a constructor, getters for each field, setters 60 00:02:53.639 --> 00:02:55.639 maybe equals hash code sash string. 61 00:02:55.960 --> 00:03:00.159 Ough. Yeah, even with helper libraries like Lombac, it's still ceremony. 62 00:03:00.240 --> 00:03:00.599 It is. 63 00:03:01.319 --> 00:03:04.080 Now compare that to colin. You can often achieve the 64 00:03:04.120 --> 00:03:08.120 exact same thing with a single line like this data 65 00:03:08.159 --> 00:03:12.520 class hexagon data class val x int val y int 66 00:03:12.599 --> 00:03:13.039 val z. 67 00:03:13.479 --> 00:03:14.520 Wow. Okay, that's it. 68 00:03:14.599 --> 00:03:17.719 That's it. That one line gives you the properties equals 69 00:03:17.759 --> 00:03:22.080 hash code two string, and even a useful copy function. Automatically. 70 00:03:22.199 --> 00:03:23.039 That is concise. 71 00:03:23.400 --> 00:03:26.680 Huge difference, massive, and it's not just data classes. Think 72 00:03:26.719 --> 00:03:27.919 about string formatting. 73 00:03:28.080 --> 00:03:31.080 Yeah, Java's string dot format or just plus signing strings 74 00:03:31.080 --> 00:03:32.680 together can get messy, right. 75 00:03:32.599 --> 00:03:35.879 Colin has string templates or interpolation. It's much cleaner. You 76 00:03:35.919 --> 00:03:39.039 can just write something like fun to human readable format 77 00:03:39.879 --> 00:03:43.159 Java user name age age. See how the variables are 78 00:03:43.199 --> 00:03:43.759 right in the string. 79 00:03:43.800 --> 00:03:44.840 Yeah, that's much clearer. 80 00:03:45.120 --> 00:03:47.960 And you can even put expressions or function calls inside 81 00:03:48.240 --> 00:03:51.879 fun to human readable format with method call Java user 82 00:03:52.280 --> 00:03:53.759 name dot capitalize. 83 00:03:53.800 --> 00:03:55.599 Oh nice, so you can call capitalize right there. 84 00:03:55.800 --> 00:03:57.919 Yep, super readable, super convenient. 85 00:03:58.400 --> 00:04:02.199 Okay, So it's clearly guided manages over Java inconciseness and 86 00:04:02.240 --> 00:04:06.120 some safey features. What about Scala You mentioned that earlier, right. 87 00:04:06.080 --> 00:04:11.159 Scala another JVM language also known for functional programming. Scala 88 00:04:11.240 --> 00:04:14.280 sometimes gets a reputation for being, as the guide puts it, 89 00:04:14.599 --> 00:04:16.199 intriguing and frightening. 90 00:04:16.439 --> 00:04:16.920 Frightening. 91 00:04:17.000 --> 00:04:21.439 Why, well, it dives deep into some pretty advanced functional concepts, 92 00:04:21.720 --> 00:04:25.439 higher kinded types, category theory stuff. It can have a 93 00:04:25.439 --> 00:04:30.360 steeper learning curve. Oh okay, and sometimes longer compile times 94 00:04:30.399 --> 00:04:31.600 have been a factor historically. 95 00:04:31.959 --> 00:04:34.399 So how does Cotland compare. Is it just as complex? 96 00:04:34.920 --> 00:04:37.839 That's the interesting part. The guide says Cotland is similar, 97 00:04:37.920 --> 00:04:41.839 but only slightly similar in every aspecting it means. Cotland 98 00:04:41.920 --> 00:04:46.680 gives you powerful functional features, maps, filters, folds, lambdas, but 99 00:04:46.800 --> 00:04:50.319 generally without the really complex abstract stuff from Scala. If 100 00:04:50.360 --> 00:04:53.439 you're a Java dev who's used Java eight streams and lambdas, 101 00:04:53.439 --> 00:04:56.040 you'll feel pretty comfortable with Cotland's functional side. 102 00:04:56.079 --> 00:04:58.360 So it's like functional programming made more approachable. 103 00:04:58.519 --> 00:05:00.879 That's a good way to put it. More pragmate, perhaps 104 00:05:01.399 --> 00:05:02.279 less academic. 105 00:05:02.759 --> 00:05:05.680 And what about fitting in with existing Java projects? Is 106 00:05:05.680 --> 00:05:06.399 it all or nothing? 107 00:05:06.680 --> 00:05:09.079 Not at all? That's a huge selling point. Cotland is 108 00:05:09.079 --> 00:05:13.199 one hundred percent compatible with Java, one hundred percent runs 109 00:05:13.199 --> 00:05:16.519 on the JVM, compiles to Java byte code. You can 110 00:05:16.560 --> 00:05:19.920 call Java code from Cotland and Cotland code from Java seamlessly. 111 00:05:20.160 --> 00:05:20.519 Wow. 112 00:05:20.680 --> 00:05:23.360 Okay, So you can introduce it gradually exactly, You can 113 00:05:23.360 --> 00:05:26.079 start using it in parts of your existing Java application. 114 00:05:26.560 --> 00:05:29.519 It matches well with existing Java code, As the guide says, 115 00:05:29.800 --> 00:05:34.680 you get to keep using the whole Java ecosystem, libraries, frameworks. 116 00:05:34.120 --> 00:05:36.920 Tools, and you mentioned it can even compile the JavaScript. 117 00:05:37.120 --> 00:05:40.600 It can, which opens up possibilities for sharing code between 118 00:05:40.600 --> 00:05:44.600 your back end and front end, potentially programming both in Cotland. 119 00:05:44.199 --> 00:05:48.240 That's pretty compelling. So summarizing the why, it seems Cotlan 120 00:05:48.319 --> 00:05:52.439 aims to fix Java's pain points, offers approachable functional programming, 121 00:05:52.680 --> 00:05:54.920 and works perfectly with Java pretty much. 122 00:05:55.000 --> 00:05:57.279 The guide says it solves many problems in Java, but 123 00:05:57.519 --> 00:05:59.480 adds only a thin layer of complexity. 124 00:05:59.560 --> 00:06:03.120 And speaking for you, the listener, why should you care? 125 00:06:03.360 --> 00:06:06.439 Well? The source puts it bluntly. It helps you pay 126 00:06:06.439 --> 00:06:08.040 bills and is so easy to use. 127 00:06:08.240 --> 00:06:10.879 Huh. Okay, maybe a bit simplistic, but the point is clear. 128 00:06:11.160 --> 00:06:15.560 Developer productivity, fewer errors, faster development that translates to. 129 00:06:15.560 --> 00:06:19.360 Value absolutely less frustration, more getting things done. 130 00:06:19.480 --> 00:06:21.759 Okay, let's shift gears slightly and dig into some of 131 00:06:21.800 --> 00:06:25.480 Colin's core features. How does it handle basic things like 132 00:06:25.600 --> 00:06:27.079 data types and control flow? 133 00:06:27.360 --> 00:06:31.759 Right? The fundamentals. Even here there are some neat twists 134 00:06:32.120 --> 00:06:34.759 like what well? First off, in Cotlin, pretty much every 135 00:06:34.839 --> 00:06:36.279 element is an object. 136 00:06:36.399 --> 00:06:38.519 Everything's an object, even basic numbers. 137 00:06:38.360 --> 00:06:41.839 Yep means you can call member functions and properties on 138 00:06:42.000 --> 00:06:44.240 any variable which has a nice consistency. 139 00:06:44.519 --> 00:06:47.600 Interesting, What about numbers specifically, or are they like Java's 140 00:06:47.680 --> 00:06:49.519 int float, et cetera similar. 141 00:06:49.639 --> 00:06:52.240 Yeah, you have INNT double float bite and so on, 142 00:06:52.600 --> 00:06:55.560 But there's a key difference in conversions. Coughlin doesn't do 143 00:06:55.720 --> 00:06:59.480 implicit widening conversions, so you can't just assign a byte 144 00:06:59.560 --> 00:07:01.600 value to an int variable directly. 145 00:07:02.040 --> 00:07:06.279 So in my byte like in Java wouldn't work correct. 146 00:07:06.279 --> 00:07:09.079 You have to explicitly say my byte dot tarrant. It 147 00:07:09.120 --> 00:07:11.360 forces you to be clear about the conversion. 148 00:07:11.120 --> 00:07:15.120 Makes sense, prevents accidental data loss or unexpected behavior exactly. 149 00:07:15.199 --> 00:07:18.160 Oh. And a small but nice feature for readability, you 150 00:07:18.160 --> 00:07:21.759 can use underscores in number literals. Underscore Yeah, like wall 151 00:07:21.839 --> 00:07:25.759 one million equals one hundred thousand zero makes large numbers 152 00:07:26.079 --> 00:07:27.079 way easier to read. 153 00:07:27.439 --> 00:07:29.120 That is neat. Okay, what about strings? 154 00:07:29.319 --> 00:07:32.720 Strings are immutable like in Java, you can iterate through 155 00:07:32.720 --> 00:07:36.360 the characters easily using a for loop for c and strings. 156 00:07:36.519 --> 00:07:38.879 A cool feature is raw text. 157 00:07:38.600 --> 00:07:39.759 Strings Raw texts. 158 00:07:39.800 --> 00:07:43.160 Yeah, you use triple quotes do inside these you can 159 00:07:43.199 --> 00:07:46.399 have new lines and special characters without needing escape sequences 160 00:07:46.439 --> 00:07:47.199 like n oh. 161 00:07:47.199 --> 00:07:50.920 That's useful for embedding like JSON or sequel. 162 00:07:50.600 --> 00:07:53.680 Snippets precisely, And you can use a function called trim 163 00:07:53.720 --> 00:07:58.199 margin to nicely format, multiline raw strings, removing leading white space. 164 00:07:58.279 --> 00:08:01.120 Andy, and you mentioned string templates earlier. 165 00:08:00.879 --> 00:08:04.000 Right, The name or expression syntax for embedding values directly 166 00:08:04.000 --> 00:08:05.480 into strings. Very convenient. 167 00:08:05.560 --> 00:08:09.240 Okay, Let's talk control flow if for a while. Any 168 00:08:09.279 --> 00:08:10.000 surprises there. 169 00:08:10.360 --> 00:08:13.959 The if statement is quite interesting. In Cotland. If is an. 170 00:08:13.879 --> 00:08:16.120 Expression an expression meaning it returns a. 171 00:08:16.160 --> 00:08:18.959 Value exactly, So you don't need a separate ternery operator 172 00:08:19.079 --> 00:08:22.279 like condition dot value t dot value of false. You 173 00:08:22.319 --> 00:08:25.680 can just write vale result if condition some value else 174 00:08:25.720 --> 00:08:29.160 another value. Ah. Okay, so the result of the if 175 00:08:29.199 --> 00:08:32.720 block gets assigned directly. Cleaner, much cleaner. Then there's when. 176 00:08:32.960 --> 00:08:33.519 When is that? 177 00:08:33.600 --> 00:08:37.320 Like switch and Java, it's Cotland's much more powerful alternative 178 00:08:37.320 --> 00:08:39.759 to Swiss shadow. It's super flexible. You can match against 179 00:08:39.759 --> 00:08:43.759 specific values, multiple values zero, one point zero ranges and 180 00:08:43.799 --> 00:08:47.159 one point sero check types is string, or even use 181 00:08:47.279 --> 00:08:48.960 arbitrary expressions as conditions. 182 00:08:48.960 --> 00:08:50.759 Wow, sounds way more versatile than switch. 183 00:08:50.879 --> 00:08:54.279 It really is, And just like if, when can also 184 00:08:54.360 --> 00:08:56.559 be used as an expression that returns a value. 185 00:08:56.799 --> 00:08:59.840 Nice. What about loops for loops? 186 00:09:00.320 --> 00:09:03.600 Standard for item in collection works as you'd expect for 187 00:09:03.720 --> 00:09:06.639 looping over arrays or lists where you need the index 188 00:09:06.679 --> 00:09:08.399 You can use a rate out indices which gives you 189 00:09:08.440 --> 00:09:11.120 a range of indices, or even better, a rate out 190 00:09:11.159 --> 00:09:14.519 with index, which gives you pairs of index value in 191 00:09:14.559 --> 00:09:16.600 each iteration. Very convenient. 192 00:09:16.799 --> 00:09:20.279 Yeah. Avoids manual index tracking and while loops while one 193 00:09:20.320 --> 00:09:22.799 do while it are pretty much standard, similar to how 194 00:09:22.799 --> 00:09:25.200 they work in Java or other SE style languages. No 195 00:09:25.279 --> 00:09:29.000 big surprises there. Okay, so far Cotland seems focused on 196 00:09:29.080 --> 00:09:34.120 conciseness and adding practical improvements to familiar concepts. Let's move 197 00:09:34.200 --> 00:09:38.159 up a level to how programs are structured classes. 198 00:09:38.000 --> 00:09:39.639 Objects, right, the building block. 199 00:09:39.679 --> 00:09:42.480 How do you define a class? Still class? Yep. 200 00:09:42.840 --> 00:09:46.960 Declaring a class is simple class invoice, but creating an 201 00:09:46.960 --> 00:09:47.960 instance is different. 202 00:09:48.200 --> 00:09:49.639 Also, no new keyword. 203 00:09:49.840 --> 00:09:54.720 You just call the constructor like a regular function veil invoice, invoice. 204 00:09:54.440 --> 00:09:56.360 Uh, simpler. What about constructors. 205 00:09:56.440 --> 00:09:59.080 Potland has a concept of a primary constructor, which is 206 00:09:59.120 --> 00:10:01.440 part of the class head itself, and you can also 207 00:10:01.480 --> 00:10:05.120 have secondary constructors declared with the constructor keyword inside the 208 00:10:05.120 --> 00:10:08.159 class body. Any initialization code that needs to run for 209 00:10:08.200 --> 00:10:10.799 the primary constructor goes into in it blocks. 210 00:10:11.000 --> 00:10:14.159 And you mentioned earlier that property declaration can be very concise. 211 00:10:14.600 --> 00:10:18.159 Yeah, this ties into the primary constructor, You can declare 212 00:10:18.200 --> 00:10:21.919 properties and initialize them directly in the primary constructor's signature, 213 00:10:22.360 --> 00:10:27.600 like class person full first name string, VOWL, last name string, var, 214 00:10:27.759 --> 00:10:32.240 age int that declares three properties first name, last name, age, 215 00:10:32.440 --> 00:10:36.080 and the primary constructor takes arguments to initialize them. Vall 216 00:10:36.279 --> 00:10:38.440 means read only, var means mutable. 217 00:10:38.639 --> 00:10:42.240 Again, very concise compared to Java's constructor boiler plate definitely. 218 00:10:42.320 --> 00:10:44.720 What about inheritance, Can any class be extended? 219 00:10:44.799 --> 00:10:47.120 Nope? By default Cotland classes are. 220 00:10:47.039 --> 00:10:50.440 Final final, meaning they cannot be inherited from correct. 221 00:10:50.519 --> 00:10:52.639 If you want a class to be inheritable, you have 222 00:10:52.720 --> 00:10:55.399 to explicitly market with the open keyword. 223 00:10:55.039 --> 00:10:57.360 Okay, so it's opt in inheritance exactly. 224 00:10:57.720 --> 00:11:00.440 Sam goes for methods or properties you want over rune, 225 00:11:00.679 --> 00:11:02.799 the method in the base class must be marked open, 226 00:11:02.840 --> 00:11:05.320 and the overwriting method in the derived class must be 227 00:11:05.399 --> 00:11:06.320 marked override. 228 00:11:06.399 --> 00:11:09.000 So it's very explicit. You have to declare your intention 229 00:11:09.159 --> 00:11:11.600 to allow extension or overwriting. Right. 230 00:11:11.679 --> 00:11:15.279 It avoids accidental inheritance or overwriting and makes APIs clearer. 231 00:11:15.399 --> 00:11:19.679 What about static methods like utility functions associated with a 232 00:11:19.720 --> 00:11:23.759 class but not an instance. Java uses static Colin. 233 00:11:23.519 --> 00:11:25.759 Doesn't have a static keyword in the same way. For 234 00:11:25.799 --> 00:11:29.480 functions that don't need class instance access, you can just 235 00:11:29.559 --> 00:11:32.159 define them at the top level of a file outside 236 00:11:32.200 --> 00:11:35.200 any class package level functions. Okay, but if you want 237 00:11:35.279 --> 00:11:39.039 functions or properties tied conceptually to a class, like factory, 238 00:11:39.080 --> 00:11:42.360 methods or constants, you use a companion. 239 00:11:41.879 --> 00:11:43.200 Object companion object. 240 00:11:43.240 --> 00:11:45.519 Yeah, it's an object declared inside a class with the 241 00:11:45.559 --> 00:11:48.639 companion keyword. You can then call its members using the 242 00:11:48.639 --> 00:11:52.960 class name directly like my class dot create, similar to 243 00:11:53.000 --> 00:11:54.799 how you'd call a static method in Java. 244 00:11:55.080 --> 00:11:57.399 So it serves a similar purpose to static it. 245 00:11:57.320 --> 00:12:00.759 Does, but it's actually a real object at runtime, meaning 246 00:12:00.919 --> 00:12:05.679 the companion object itself can implement interfaces or have extension functions, 247 00:12:05.720 --> 00:12:08.000 which is more powerful than Java static members. 248 00:12:08.120 --> 00:12:12.039 Interesting distinction. Let's talk more about properties val and var right. 249 00:12:12.399 --> 00:12:16.000 Val for read only like Java final fields, var, forer 250 00:12:16.120 --> 00:12:17.559 mutable pretty straightforward. 251 00:12:17.600 --> 00:12:21.200 Can you customize how they work like custom getters or setters? 252 00:12:21.519 --> 00:12:25.000 Absolutely. You can define custom get and set logic right 253 00:12:25.039 --> 00:12:29.279 after the property declaration. For example, val is empty oulian 254 00:12:29.360 --> 00:12:32.879 get this dot size equals hour zero. This defines a 255 00:12:32.960 --> 00:12:35.679 read only is empty property whose value is calculated by 256 00:12:35.720 --> 00:12:37.120 the getter each time it's accessed. 257 00:12:37.240 --> 00:12:41.240 Got it. What about properties that can't be initialized immediately 258 00:12:41.240 --> 00:12:43.919 in the constructor maybe they're set up by a dependency 259 00:12:43.919 --> 00:12:45.200 injection framework later. 260 00:12:45.399 --> 00:12:48.799 Ah, good question for that. Cotlin has the latin it 261 00:12:48.960 --> 00:12:52.200 modifier latina. Yeah. You mark a var property with a 262 00:12:52.279 --> 00:12:54.919 Latin it tells the compiler trust me, this non null 263 00:12:54.960 --> 00:12:57.279 property will be initialized before I try to use it. 264 00:12:57.600 --> 00:12:59.879 This lets you avoid initializing it to null just to 265 00:13:00.000 --> 00:13:02.960 satisfy the compiler, and then you don't need null checks 266 00:13:03.000 --> 00:13:03.720 everywhere later. 267 00:13:03.879 --> 00:13:06.879 Okay, that handles a common scenario nicely. Now the guide 268 00:13:06.919 --> 00:13:11.240 mentions something called delegated properties. That sounds advanced. 269 00:13:11.360 --> 00:13:14.200 It's a really powerful concept, actually, maybe one of Cotland's 270 00:13:14.240 --> 00:13:16.919 killer features. The idea is you can delegate the getter 271 00:13:16.960 --> 00:13:20.159 and setter logic of a property to another object. 272 00:13:20.159 --> 00:13:21.799 A delegate delegate the largic. 273 00:13:22.519 --> 00:13:26.639 Why it lets you reuse common property behaviors without writing 274 00:13:26.639 --> 00:13:29.960 boilerplate code over and over. The guide says, you can 275 00:13:30.000 --> 00:13:32.759 define the use of properties manually over and over again, 276 00:13:33.240 --> 00:13:35.879 but then store this definition in the library for use 277 00:13:35.919 --> 00:13:36.600 whenever needed. 278 00:13:36.720 --> 00:13:38.200 Okay, like what kind of behaviors? 279 00:13:38.320 --> 00:13:42.440 Common examples built into the standard library include lazy properties 280 00:13:42.559 --> 00:13:45.440 lazy yeah, The value of a lazy property is computed 281 00:13:45.519 --> 00:13:47.279 only the first time you access it, and then the 282 00:13:47.279 --> 00:13:50.840 result is cased. Great for expensive initializations you might not 283 00:13:50.960 --> 00:13:51.840 always need. 284 00:13:52.000 --> 00:13:54.480 I see performance optimization exactly. 285 00:13:54.720 --> 00:13:58.159 Another one is observable properties. You provide a handler function 286 00:13:58.240 --> 00:14:00.879 that gets called every time the property value changes. 287 00:14:01.120 --> 00:14:04.240 Useful for like updating UI or logging changes. 288 00:14:04.360 --> 00:14:07.080 Perfect for that. You can even delegate properties to store 289 00:14:07.120 --> 00:14:08.200 their values in a map. 290 00:14:08.480 --> 00:14:12.039 Wow. So it's a way to abstract common property patterns 291 00:14:12.039 --> 00:14:13.279 into reusable delegates. 292 00:14:13.320 --> 00:14:16.720 Precisely, it cleans up codes significantly by handling things like 293 00:14:16.840 --> 00:14:21.039 lazy loading, observation, or even mapping properties to external data 294 00:14:21.080 --> 00:14:22.759 sources in a standard way. 295 00:14:23.080 --> 00:14:26.919 That sounds incredibly useful. Okay, let's zoom out again. We've 296 00:14:26.919 --> 00:14:30.480 covered syntax and core features. How does this all come 297 00:14:30.519 --> 00:14:34.679 together the broader developer experience? How is cotlin actually used well? 298 00:14:34.720 --> 00:14:38.000 Besides Android, it's making huge strides in server side development. 299 00:14:38.159 --> 00:14:42.159 Server side, with Java being so dominant that yep, Colin. 300 00:14:41.919 --> 00:14:44.879 Is seen as a powerful tool for servers. It brings 301 00:14:44.879 --> 00:14:48.559 that expressiveness and safety we talked about. Plus, it has 302 00:14:48.639 --> 00:14:52.320 excellent support for concurrency with coroutines, which are very lightweight 303 00:14:52.440 --> 00:14:55.480 compared to traditional threads leading to better scalability core to 304 00:14:55.559 --> 00:14:59.840 teams right heard about those, And crucially that Java Interopera 305 00:15:00.480 --> 00:15:04.080 means you can adopt it gradually in existing Java server applications. 306 00:15:04.120 --> 00:15:06.080 It supports a step by step transition. 307 00:15:06.320 --> 00:15:08.720 Are major framework supporting it like Spring? 308 00:15:09.000 --> 00:15:12.720 Absolutely? Spring has first class Coughtland support dot x two 309 00:15:13.159 --> 00:15:16.200 And there are Cotland native frameworks like Creator developed by 310 00:15:16.279 --> 00:15:17.360 jet Brains themselves. 311 00:15:17.440 --> 00:15:19.440 And are there big real world examples? 312 00:15:19.600 --> 00:15:22.159 The guide mentions a couple of fascinating ones. The corna 313 00:15:22.200 --> 00:15:25.639 platform that's an open distributed ledger platform used by major 314 00:15:25.720 --> 00:15:29.320 banks for financial records, is built entirely in Cotlin entirely 315 00:15:29.440 --> 00:15:33.600 wow Yeah, And jet Brain's own licensing system. Jet Brain's 316 00:15:33.600 --> 00:15:37.159 account has apparently been running on Cotland since twenty fifteen 317 00:15:37.480 --> 00:15:40.240 without major problems, so it's battle tested. 318 00:15:40.440 --> 00:15:43.759 That's strong evidence of its maturity for server use. Okay, 319 00:15:43.840 --> 00:15:48.840 beyond the language itself, what about conventions, style, guides, best practices. 320 00:15:49.120 --> 00:15:55.279 Cotland generally follows established Java conventions for naming things, packages, classes, functions, properties, so. 321 00:15:55.320 --> 00:15:58.080 Camel case for functions and variables, Pascal case. 322 00:15:57.919 --> 00:16:01.480 For classes exactly. Constants tend to be all caps with underscores. 323 00:16:01.879 --> 00:16:06.679 Pretty standard stuff, formatting tabs or spaces brace style. 324 00:16:06.480 --> 00:16:10.440 The official recommendation is four spaces for indentation. Brace style 325 00:16:10.559 --> 00:16:12.679 is similar to Java opening brace at the end of 326 00:16:12.720 --> 00:16:15.240 the line, closing brace on its own line, and a 327 00:16:15.279 --> 00:16:18.279 small but lovely detail. The guide points out semi collins 328 00:16:18.320 --> 00:16:19.399 at the end of lines are. 329 00:16:19.320 --> 00:16:22.480 Optional, optional semicolons. That's always a crowd pleaser, isn't it? 330 00:16:22.600 --> 00:16:24.360 Just it cleans things up visually? 331 00:16:24.639 --> 00:16:27.600 What about recommended coding patterns? Does the call in community 332 00:16:27.639 --> 00:16:28.840 push certain styles? 333 00:16:29.000 --> 00:16:31.519 Definitely? A big one is immutability. 334 00:16:31.080 --> 00:16:32.480 Using val over var. 335 00:16:32.840 --> 00:16:36.879 Yes, strongly encouraged. It is preferable to use static data 336 00:16:37.000 --> 00:16:40.799 on the variable. The guide says favor val. Use immutable 337 00:16:40.799 --> 00:16:45.080 collection interfaces list set map rather than mutable list, et 338 00:16:45.159 --> 00:16:46.240 cetera whenever you. 339 00:16:46.240 --> 00:16:48.200 Can why the emphasis makes. 340 00:16:48.000 --> 00:16:51.240 Code easier to reason about, less prone to bugs caused 341 00:16:51.240 --> 00:16:54.720 by unexpected state changes, especially in concurrent scenarios. 342 00:16:54.840 --> 00:16:57.120 Makes sense any other key patterns. 343 00:16:56.840 --> 00:17:00.519 Default parameter values are heavily used. Instead of writing multiple 344 00:17:00.559 --> 00:17:03.919 overloaded functions, you just define default values for parameters in 345 00:17:03.960 --> 00:17:08.240 a single function declaration leads to much cleaner APIs. 346 00:17:07.799 --> 00:17:11.519 Right, avoids that explosion of method signatures thick exactly. 347 00:17:12.119 --> 00:17:16.519 Also destructuring declarations. Destructuring was that it's a concise way 348 00:17:16.559 --> 00:17:19.759 to unpack an object into multiple variables. Remember the data 349 00:17:19.759 --> 00:17:23.359 class person, vowel, name, string, vowel age into Yeah, you 350 00:17:23.359 --> 00:17:27.480 can write vowelname, age, person instance. Cotlan automatically calls generated 351 00:17:27.480 --> 00:17:31.039 component one and component two functions to extract the values 352 00:17:31.079 --> 00:17:32.440 into name and age variable. 353 00:17:32.519 --> 00:17:36.279 Oh, needs you know to vowel name person dot name vowelage, 354 00:17:36.359 --> 00:17:37.400 person dot age. 355 00:17:37.480 --> 00:17:41.559 Correct. It's super useful when functions return multiple values, often 356 00:17:41.640 --> 00:17:45.279 via a data class or pair, or when iterating over maps. 357 00:17:45.359 --> 00:17:46.480 How does it work with maps? 358 00:17:46.599 --> 00:17:51.359 You can loop like this for key value in my map. 359 00:17:51.640 --> 00:17:52.200 Very elegant. 360 00:17:52.240 --> 00:17:55.240 That is elegant. Also, ranges are used a lot for loops, 361 00:17:55.599 --> 00:17:59.519 using until for exclusive ranges for i and zero, intel 362 00:17:59.599 --> 00:18:03.119 size comments size, and you have down to and step 363 00:18:03.240 --> 00:18:03.960 for more control. 364 00:18:04.440 --> 00:18:07.759 Okay, what about those smart casts mentioned in the guide? Ah? 365 00:18:07.839 --> 00:18:10.400 Yes, smart casts are great. Basically, if you perform a 366 00:18:10.480 --> 00:18:13.559 type check like if X is string, the compiler is 367 00:18:13.599 --> 00:18:17.440 smart enough to automatically treat X as a string inside that. 368 00:18:17.440 --> 00:18:19.839 Block, so you don't need to explicitly cast it again. 369 00:18:19.960 --> 00:18:23.519 Often no, the compiler automatically converts and securely when needed 370 00:18:23.559 --> 00:18:26.000 within that scope, reduces casting. 371 00:18:25.680 --> 00:18:30.240 Clutter, and finally, exceptions. Java has checked exceptions, which can 372 00:18:30.279 --> 00:18:33.000 be controversial. How does Cotlin handle them? 373 00:18:33.039 --> 00:18:35.400 Cotland gets rid of them entirely. It does not support 374 00:18:35.519 --> 00:18:36.920 checked exceptions. 375 00:18:36.400 --> 00:18:37.759 No checked exceptions at all. 376 00:18:38.119 --> 00:18:41.920 Nope, it's a deliberate design choice. The thinking is that 377 00:18:41.960 --> 00:18:46.039 forcing tricatch blocks for checked exceptions often leads to boilerplate 378 00:18:46.079 --> 00:18:50.240 code that doesn't actually handle the error meaningfully, reducing productivity. 379 00:18:50.599 --> 00:18:53.960 So all exceptions are effectively unchecked like runtime exceptions in Java. 380 00:18:54.039 --> 00:18:56.759 Pretty much. Yes, it puts the onus on the developer 381 00:18:56.839 --> 00:19:00.720 to decide when and how to handle potential exceptions rather 382 00:19:00.799 --> 00:19:02.480 than forcing it through the type system. 383 00:19:02.960 --> 00:19:07.079 Interesting, definitely different philosophy. Okay, so wrapping things that we've 384 00:19:07.079 --> 00:19:10.880 gone through quite a journey here from Cotland's core philosophy 385 00:19:11.160 --> 00:19:12.759 compared to Java and Scala. 386 00:19:12.880 --> 00:19:18.000 Yeah, focusing on that conciseness, safety, and interoperability. 387 00:19:17.160 --> 00:19:21.200 To its specific features like data classes, null safety, when expressions, 388 00:19:21.240 --> 00:19:23.839 companion objects, delegated properties. 389 00:19:23.319 --> 00:19:28.279 And the powerful conventions like immutability, default parameters, and smart casts. 390 00:19:28.680 --> 00:19:31.720 It really feels like a language designed with developer productivity 391 00:19:31.839 --> 00:19:34.119 and dare I say happiness in mind, I. 392 00:19:34.039 --> 00:19:37.200 Think that's fair. It addresses many common frustrations and provides 393 00:19:37.279 --> 00:19:40.519 elegant solutions while staying practical and interoperable. 394 00:19:40.799 --> 00:19:43.119 So for you listening, you should now have a much 395 00:19:43.160 --> 00:19:46.640 clearer picture of what Cotland is, why it's gained so 396 00:19:46.720 --> 00:19:48.839 much traction, and the kind of problems it solves. 397 00:19:48.880 --> 00:19:51.960 Ejectively, you've got a solid grasp of what makes it 398 00:19:52.079 --> 00:19:55.720 well that breath of fresh air. For many developers, it's pragmatism, 399 00:19:55.920 --> 00:19:59.400 it's clever features, and its strong ecosystem for building various 400 00:19:59.480 --> 00:20:00.599 kinds of app iplations. 401 00:20:00.759 --> 00:20:03.200