Kotlin Crash Course

[@PhilippLackner]

Thanks for the opportunity Brad, and I hope you guys like Kotlin! :)

[@eren1514]

Good work mate! You deserved to be here *Eronred :)*

[@PhilippLackner]

@@eren1514 Yo, thanks man :)

[@amano_akane]

Wooooow Philip here you are again. Remember me ?

[@gauravthakkar802]

Yayy

[@TheVertical92]

good to see a fellow german here 👍

[@samha1513]

i like how he explains the abstract class with example. well done!

[@Dheemantha]

great tutorial, I am a java developer newly entering to the kotlin programming and this covers kind of all the things for me. Thanks and keep up the good work.

[@branmuller]

Wow you should make a udemy course. You explained the concepts soooo well! I will come back to this video if i ever need a refresher for OOP

[@KeithDCommiskey]

​For anyone who finds there is no "File -> New -> Kotlin Class/File" option, you may have to mark the top folder (in the Project pane; with the project path next to it) as being the "Sources Root". Right-click the folder and use the "Mark Directory as... -> Source Root" option. Then the "Kotlin Class/File" option should become available from the "File -> New" menu.

[@JordanTheImpaler69]

This is exactly the issue I was dealing with. Thank you so much.

[@Lucas-hh4oh]

This is the best kotlin crash course, I've ever found on youtube! Really good video for a refresher

[@jonasnghidengwa7186]

Damn,,, bro this is crystal 🔮 you have really explained everything to the extent that ,,, even those that do not have an idea what programming is ,can grasp everything... Thank you for this bro keep up💙🤜🤛🙏

[@wondersled5948]

You're an amazing teacher! All of the concepts were masterfully explained, and I grasped them almost immediately. I'll mess around with Kotlin a little to get a hold of its in and outs, and then I'll watch your video lesson on app development. Thanks again!

[@WZLR]

Kotlin is my favourite language of the ones I’ve used. Syntactically it is beautiful and it just makes sense.

[@jesusbohorquez2098]

Bro, you are amazing, I have been struggling with Android because almost all tutorials overcomplicate things, yet , you on the other hand, you make it so simple. Thank you, pal

[@Shrooblord]

Thanks a lot! Very nice and thorough introduction. You pointed out some great little nuances about the language that already make me excited to get started. :) For extra credit, the final function you write -- the generic customCount() extension... if we want to be 'clean', we should rename the variable 'string' to something like 'type'. So, "for (type in this)" etc. It pays off to have your variables named properly ;)

[@Asifkabeer]

Watched the entire thing as I practiced in IntelliJ. Super helpful. This was my introduction to Kotlin and I cant say enough how simple you made it. Thank you so much Philip.

[@jordigarciapena7180]

Nice job Philipp! I'm intending to move from Java to Kotlin and I was looking for a nice way to dive in! This video just did the trick! Thanks really!

[@aprendendoviolaoem5minutos600]

Perfect introduction of Kotlin for begginners, thank you!

[@banszkiviktoria]

"Lamborghini, Penthouse, Rolex.... just a normal purchase for a programming KZbinr..." :D :D :D

[@suneet2193]

Just to put it out there...I was not able to RUN the code initially...it just showed the 'EDIT CONFIGURATIONS' option. The solution was to just press RIGHT CLICK on "src" Folder ---> Mark Directory as ---> Sources Root.

[@LaurentLaborde]

Best real world explanation of abstract class i ever heard.

[@BlueIsLeet]

This video really got me going on kotlin and helped me understand it. Thanks

[@AbdallahSamir-x4w]

Thank you for this crash course and we need more videos like this.

[@alessandrod.306]

Very good video for beginners I really liked the examples and the way you explain everything. Keep up the good work.

[@alejrandom6592]

I love how he casually throws in a Lambo in his shopping list

[@MysticMac000]

Amazing course, thank you! I will watch your Android course next

[@DevMadeEasy]

Great content, thanks for sharing it!

[@GGShinobi77]

36:12 Shopping List: Lamborghini, Penthouse, Rolex... hey how did you get the contents of my shopping list!? XD

[@cnorris1193]

3/16/2021; my version of IntelliJ does not have the same options; from installation as far as @10:43 I'm trying to follow along, but I cannot however, you are an excellent instructor and I approve of this video

[@steelcardoza5361]

Having the same issue, when I right click on .src I can't create a .kt file. I can create a .kts file though.

[@hilmiamir3514]

Well done. Very precise for beginners!

[@magicmedia7950]

Can't wait for the day coding tutorials will be made mobile phone friendly

[@themindsetgarage]

kotlin all the way.Would love to learn more on ktor language

[@Nae_Ayy]

i dont understand everything is completely different than the tutorial is showing, all the options are different

[@redus2]

Awesome video man, thanks a bunch!

[@dreddirt]

I am new to app development and I can see how this crash course can help me. This new version of Intellij IDEA will ask me to choose Target JVM version and Test framework when adding a new project. If you can help me out, that would be really amazing.

[@therealfodder]

The lack of semi-colons gives me the jeebies! (jk!) Great video - I need to move to Kotlin and this gives an excellent starting point.

[@clemthompson5336]

Thank you !!!!

[@davebudah]

Yeah now that's something. Thanks.

[@KROMMASyS]

Awesome course, thanks

[@MonaDangerW]

Hey! Is there a new updated video? The programs are updated and dont look the same anymore. Thanks

[@dr.schultz9023]

thanks buddy your explanation is good.

[@allainecaalaman8672]

Thank you so much for this

[@lewistaylor4620]

Kotlin is like a mix between c and java

[@artyomfromsib]

Tbh "for" command didn't make sense. I just couldn't get it

[@rajmoulijujjavarapu3677]

May I ask why the string in the for function not with a capital s. well it is working perfectly, but I don't know why it is not a capital 'S'

[@carlitodidthat]

cant seem to get kotlin to work ive watched so many videos and everything is different and nothing works

[@EmbeddedSorcery]

I never agreed with the language 'choosing' a naming convention. It's more important to adapt to the team, and specifically the people that will review your code so it's quicker for them. But saying "Kotlin uses this naming convention" is just silly. It's easy to switch to whatever you need to. In C++ I prefer camel case with constexpr, and snake case with in-scope, on-stack variables.

[@saatvikmangal7994]

Thank you 🙇🙇🙏🙏

[@RagHelen]

Java isn't an old language. In the league of the big ones, it is younger than C++ and Python and as old as PHP, JS and C#. It just LOOKS old, especially compared to any of the ones mentioned. And it makes me wonder, if worst of the bunch should give birth to a child.

[@aniketvarma5661]

most of the sdk in my project in java can i use them in kotlin project?

[@marnixv7824]

Hi, I can't seem to find the ''new class'' button. If press new, it only says: File, scratch file, directory

[@marnixv7824]

I now see I can only create create a new kotlin class/file on the map (in this case kotlin-crash-course). Is that how it is supposed to be?

[@haydennn1]

Is it weird that I sing the intro melody?

[@y0nd3r]

IntelliJ start failed. Java.util.concurrent.CompletionException: java.lang.IllegalStateException: failed to create a child event loop Restart didn't fix it. JetBrains "Start Failed" help page is cryptic.

[@abdallahalkhassaky9506]

Hey Brad, just wanted to let you know that I love your content man, please do some more videos on data structures and algorithms, I need some to ace my upcoming interviews ;)

[@TraversyMedia]

It is something I have been meaning to do. I was trying to think of what MY next video would be. That could be it, we'll see :)

[@SB-df8vy]

@@TraversyMedia yes please, I second this motion

[@abdallahalkhassaky9506]

@@TraversyMedia Thank you really much man, we appreciate it, I read many books and I am still struggling with some of them lol.. Keep up the good work👍

[@jacksonbodra6450]

@@TraversyMedia 1.32 M (your subs) :- YES Please !!!

[@codinginflow]

Wow 😍

[@mathumacharia6225]

Hi man, your videos introduced me to kotlin and android development. I hope you get featured in brads channel someday. Big thank you @coding_in_flow

[@pedroserapio8075]

Thanks for taking your time, hard to follow with the new IntelliJ IDEA 2021.2.

[@robertmarsman2055]

Great tutorial. But im stuck at the begging even after following the instructions. After clicking on "src ew " I do not see Kotlin Edit/class option. Version: Intellij 11.09.01

[@tomkerr8155]

Me too

[@KeithDCommiskey]

@@tomkerr8155 I also just ran into this issue. You have to mark the top folder (in the Project pane; with the project path next to it) as being the "Sources Root". Right-click the folder and use the "Mark Directory as... -> Source Root" option. Then the "Kotlin Class/File" option should become available from the File -> New menu.

[@bobbylinse6668]

Great job! That was super informative. The only feedback I'd give, is that when you're declaring a variable of type String or type fun, to use slightly different naming conventions to avoid any confusion. For example, if you're declaring a String, avoid calling it "string" and if you're declaring a function to avoid calling it "function" It just made the lambda and generics section a little bit harder to follow is all. Other than that, this was a 10/10. You did a great job explaining some of these concepts!

[@thomasgeorge7473]

I've had some trouble making a Kotlin project on the new IntelliJ IDEA 2022.2 version. You have to start with a general New Project, then select Kotlin for the langauge, select IntelliJ for build system, and also tick 'add sample code' to get it to work.

[@gpiludu]

If anyone got stuck with the Main.kt file, in IntelliJ 2020.3 (or whatever the version after the video's is), I had to put the file at src/main/kotlin/Main.kt

[@arslanrasit]

Up you go!

[@vineetranjan08]

Oh Wow. Just few hours ago I was searching for Kotlin tutorial, and here it is !

[@tomkerr8155]

I'm trying to follow this tutorial but the options and sequences are not showing the same on my version of IJ. Do you have an updated version?

[@TheRealLucifer-Morningstar]

i have the same issue

[@KeithDCommiskey]

@@TheRealLucifer-Morningstar I found there were two differences in what I was seeing and what is in the video. I posted potential solutions to both of them in the comments (sort by newest). HIH

[@bilelrahmouni01]

thnks a lot for the vid!! i have one issue: when i press enter twice on this: val number1 = readLine() ?: "0" val number2 = readLine() ?: "0" val result = number1.toInt() + number2.toInt() println(result) to give null twice it doesnt take 0 + 0 it show Exception in thread "main" java.lang.NumberFormatException: For input string: "" can anyone help me understand why pls

[@mohamedelkhames1637]

I'm not good at English but you are so amazing but Your explanation is really simple thank you so much

[@bilelrahmouni01]

Lamborghini Penthouse Rolex , .add("Ferrari") ... wow that's my shopping list for 2022 what a coincidence 😅

[@SillverBel]

(Opens Kotlin) - Kotlin not configured - No option for .kt - Won't run "Hello World!" - Red everywhere. I love code :)))))

[@MisterWealth]

My kotlin-crash-course - src has files in it, his doesn't. It has a main with kotlin and resources, then has another folder that says kotlin and resources in that one as well. What do I click? Neither are allowing me to view it..

[@ahmedn.4085]

My advice on programming for the fellow wanna be programmers is this.... Consistency is the key and if i or he can! You can too

[@kskfernando2945]

Ok

[@Salehalanazi-7]

He explains interfaces like way better than a college professor.

[@drexxboban8277]

For those in need, new version of IJ you go New Project -> select (under nodejs) JVM it is already an IDEA, and the rest is similar to his. As for creation of new kotlin files mark src as root folder by clicking right click on it and then select `Mark Directory as` and `Sources root`. Then in src->main->kotlin create new files by right click->New -> plenty to choose from.

[@andilesimelane4771]

its amazing loud and clear, thanks to Brad for making its easy fr your million subscribers to easily find out about other great teachers.

[@KeithDCommiskey]

If you are not getting the empty folder structure as shown in the video, and the "Kotlin" selection [@8:30] shows additional options not shown in the video, from the "New Project" menu, try instead selecting "Java" -> "Kotlin/JVM".

[@steelcardoza5361]

Oh my goodness thank you, I just spent the last hour trying to figure this out

[@tanzimibthesam5861]

Is Kotlin easier than Java with a bit of modern day syntax?

[@PhilippLackner]

I wouldn't say learning Kotlin is easier or harder than Java, but once you know it, you can do things easier than in Java and in less code

[@quantumcd1045]

I'm getting a "NumberFormatException" when I run the code at 35:50.

[@maruf_r]

Watch 1:08:00

[@Gokuderathestorm]

The JDK has moved and intellaJ has changed. Could you do a modern video ?

[@linusperez2158]

It has changed alot, "main" already existed for me

[@justamemer4400]

This is an excellent tutorial for beginners to understand basic concepts such as functions if else if etc; as well as for people who have learnt all the advanced concepts before in java but have never used kotlin before and are now moving to kotlin for android dev.

[@GabrielTobing]

Indeed, I'm moving over from Java and this is really helpful XD

[@notstorm]

I am having a problem when I try to create a project in my ide I have to select the build system, by selecting the default one i have many other files in my project folder such as gradle and stuff and inside the source(src) folder I have 2 more folders and 2 subfolders inside those 2 folders, and upon creating a Main.kt file I don't seem to have the run option any help will be appreciated

[@naomidemeer2445]

Hi! I had the same issue. In case you haven't figured it out yet: For me it worked to create the file under src --> main --> kotlin. All three folders already existed. By creating my new kotlin file there, I was able to get the same screens Philipp gets and run the Hello World program. Hope this helps. :)

[@notstorm]

@@naomidemeer2445 I really appreciate the help u rendered, I figured it out after experimenting myself and it worked :D and can u please update ur comment saying that u need to use "intelliJ" build to have such folders it won't work in other builds since rest of the folders aren't there :p I give my heart felt thanks to you once again

[@philekiert1251]

Thanks so much for this, this has got me up to speed enough to make a start on the little project I'm working on! Quick note for anyone new to programming confused by the lambda function syntax around an 01:20:00, "function" and "string" here are just arbitrary names for those objects, not keywords. They could just as easily be anything else.

[@jawad9757]

omg i was thinking of learning kotlin and this popped up, i think its meant to be

[@rcorreia23]

If you talked about it next to your phone or computer mic big brother google must have heard it hahahahaha

[@tamgaming9861]

When you start a new Project before - the pics all have changed, its not longer possible to follow as beginner, there are different screens now inbetween to build a new project, which is now very confusing ... so sad was in hope to follow your video.

[@erik_mueller]

While making a new project you go to java instead of kotlin and then tick box with kotlin

[@tamgaming9861]

@@erik_mueller Danke Dir, denke werde das hinbekommen, fand gerade Udemy Kurs und denke weiß was du meinst. Danke :-)

[@armadillo85]

This is such a big help! Thank you!

[@johanesalberto6136]

thanks for making me understand kotlin

[@BigWhoopZH]

To be fair Java is catching up quite a bit in recent versions. So I'm not sure if Kotlin will ever replace Java or the other way around or if they just continue to coexist. It seems like Oracle accepted the challenge. Nevertheless it is a great achievement for Jetbrains to play at the levels of Google and Oracle. And their IDEs already wiped the floor with their competitors.

[@JonnyRootsDem]

My dog function wont print "Woof"! I don't know if it's got anything to do with the version of IntelliJ I'm using, which is 2021

[@alijaun4248]

I am getting this error in my android studio while doing kotlin if someone can help Could not find method compileKotlin() for arguments [build_b8lg4v2lqwq5kin7aowknxto0$_run_closure3@4850d563] on project ':app' of type org.gradle.api.Project

[@pixelPlex]

What the presenter mentions about Kotlin adoption is very misleading, and is just spreading misinformation about Kotlin that has a heavy Android development bias (closed world view), which isn't considerate of other software development areas where Kotlin is used. With the latest Kotlin survey ( www.jetbrains.com/lp/devecosystem-2020/kotlin/ ) from JetBrains (the creator of Kotlin, NOT Google) Kotlin is mainly used for JVM (includes backend development), and Android development, which is at about the same level of adoption. The first software development area where Kotlin had its first big break is with backend development when Spring (created by Pivotal) made the Kotlin support announcement ( spring.io/blog/2017/01/04/introducing-kotlin-support-in-spring-framework-5-0 ) a few months "before" the Android announcement made by Google ( android-developers.googleblog.com/2017/05/android-announces-support-for-kotlin.html ). For the record IntelliJ is the main IDE used for software development with Kotlin, except for Android development which is covered by Android Studio. IntelliJ isn't just a IDE that one uses to learn about Kotlin. There are many businesses that use IntelliJ to do backend/JVM development with Kotlin in "commercial" projects. Backend development with Kotlin is already "widespread" ( kzbin.info/www/bejne/bqmkeWqIipWMapY ; en.wikipedia.org/wiki/Kotlin_(programming_language)#Adoption ; kzbin.info/www/bejne/rl7JmaymfrecppY ), and in more recent times Google has started to use Kotlin ( kzbin.info/www/bejne/d5izm2SHa6lgY8U&t=309 ) alongside many other businesses. A good use case to look at for Kotlin in backend development is the Atlassian presentation ( kzbin.info/www/bejne/anjOoHVqnb-IpNk ). Kotlin is a programming language that has in a short space of time become the favourite language to use by many Investment banks, and publishers for backend development. In many cases business use Kotlin instead of Java for "ALL" new software development projects (especially backend type projects), which is becoming an increasingly common pattern/business policy.

[@RahulAhire]

I'm really glad that kotlin look 80-90% exactly same as JavaScript which will help web developers learn kotlin easily for native mobile development

[@chrispengelly5503]

I'm getting completely different options to you. For example when I click Kotlin after creating a new project, JVM IDEA is not an option. I try the only JVM that comes up, but cannot run anything because it asks me to configure it, with loads of options I don't understand... has the program changed significantly since this video???

[@ReneMeier-ew4ry]

very helpful, thanks!

[@rohitkf8474]

Really loved the way he taught kotlin and explained everything so clearly. Looking forward to his android crash course. Thanks a lot Brad❤️

[@soheil424]

the version you recomend as for jdk is just sucks on windows! Have to install the real java jdk to be able to follow the tutorial.

[@punerealestatebuilder]

Lol :D don't tell a lie, Edge is your fav browser, I know that. Jokes apart, the secret is, after 11 years of experience on Android and 4 years in Kotlin, I refer to your videos for Interview purposes (as interviewer or as interviewee) :D

[@fing4186]

This was great for me ! I am coming from Java and wanted to get on board with Kotlin quick, without the unnecessary fat which you can find in most of the other courses. Thanks a a lot !

[@phobic1172]

The JKD download page at 07:00 doesn't seem to work anymore and redirects to Eclipse Temurin. Any idea what I should download from there, if anything?

[@damovex]

@Philipp Lackner so the I (OR) is referred to as the PIPE symbol So II is the Double PIPE. Thanks for sharing your knowledge. Very clear explanations. You go further than most with the syntax and some edge cases and clarifications. Very helpful.

[@JeffPohlmeyer]

I know this a general purpose video on Kotlin and not necessarily an Android app video (which is coming next) but I'd imagine the next logical step would be having someone on for a Swift tutorial, no?

[@kekekeernest8920]

Please, how can I round a number let say 1.333333334 to 1.34, in kotlin, because anytime I used the round(), it gives me an integer value

[@jamesisin]

"Real programmers choose the dark theme." The whole Internet should be dark themed. It's not made of paper!

[@mohamedhussein5106]

Very informative. I got everything except for the lambda part but that's not a big issue. SHOKRAN!

[@doubleg1094]

why kotlin ? IMO, nothing but versatility , it's the modern C#/JAVA rival

[@shibasishdas4107]

Lamborghini, Penthouse and Rolex, just a normal purchase for programming youtuber. LOL!!!

[@mali_sati]

Lamborghini, Penthouse, Rolex "Just a normal purchase as a programming youtuber" 😭😭😭

[@Asgaia]

Why do write cuddled else and catch? Thats is a really nasty style these days. Nobody (except Sun and Adobe) wrote such a style.