best kotlin tutorial

Kotlin transmits variable length parameters to Java Variable Parameter instance code, kotlinjava This article mainly studies how Kotlin transfers variable length parameters to Java variable parameters. The specific implementation code is as follows. Defines Java Variable Parameter Methods Package com. tcl. john. studymvvm. utils;/*** call Java method tool class * Created by ZhangJun on. */public class Ca

Antonio LeivaTime:Jan,Original link:Https://antonioleiva.com/anko-background-kotlin-android/Anko is an Android library developed by JetBrains with Kotlin, which can be used in many different ways. Its main feature is the use of DSL code to create a view .While this may be interesting, the fact is that I have been using XML very well for a long time. So there's not much to try with this feature.In fact, it h

Kotlin built-in numeric typeNote: Numeric types in Kotlin cannot be implicitly convertedKotlin supports binary, decimal, hexadecimal, but octal is not supportedbinary var a = 0b0011_0011 (starting with 0b)decimal var b = 999Hex var c = 0x1a4f (starting with 0x)Kotlin to create a numeric type object: 1 fun Main (Args:array 2 var int : int= 1 3 var long : Long =

Using http://start.spring.io/to download the Project Run Unit Test report java.lang.ClassNotFoundException: Kotlin.reflect.KotlinReflectionInternalErrorReason isJackson-module-kotlin version references kotlin-reflect too low by defaultThere is no such kotlinreflectioninternalerror in the new kotlin-reflect.WorkaroundDeclare specific versions of Jackson-module-

Cloudopt Next is a Kotlin, vertx-oriented, next-generation, ultra-lightweight microservices framework that allows you to handle URL parsing, data encapsulation, JSON output, and more, radically reducing development time and improving the development experience. Cloudopt next absorbs the ideas of spring Boot, jfinal, Resty, VERTX and other outstanding projects, with a very good development experience and a very low learning curve.Cloudopt Next has the

When I woke up, I suddenly found out that Google has Kotlin as the first-level development language for Android, saying that it's going to be next to Java (but I always feel that Java is being discarded, mostly oracle things do sometimes ...). , Kotlin before really did not pay attention to, open IntelliJ idea, found in fact Kotlin module already had. So quickly

View all my open source projects "open Source Labs"Welcome to join my QQ group: "257053751", this blog client download "please click"SummaryIf you really want to learn more about the Kotlin language, you can view the English version of the Kotlin language document, or my Kotlin language document Chinese translation Project KOTLINDOC-CN:HTTPS://GITHUB.COM/KYMJS/KO

Antonio LeivaTime:Dec,Original link:https://antonioleiva.com/kotlin-integrations-android-sdk/Using the Kotlin language not only simplifies your code, but it also simplifies calling Java code from Kotlin.How does this work? Simply using some common structure can get a sense of kotlin.In this article, you'll see some examples of how to promote the same code. It also prevents the Java code from including the t

1. Define Package NameConventionally, the package definition places the top of the code source file Package Com.demo.hellokotlin Import java.util.* //... This is no different from the Java definition. 2. Definition methodThe first way to get started with Java is the main method, and Kotlin main is much simpler, using the keyword Fun Declaration, as follows: Fun Main (args:array Define a sum that returns two integers, you can see that the paramete

Basic Syntax 1. Define Package name As in Java, at the head of the file Package My.demo Import java.util.* 2. Definition Method Take the following method as an example: Fun sum (A:int, b:int): Int { return a + b } Methods start with the fun keyword, a:int, and B:int as the method parameter. After the parentheses: int is the return value. The Kotlin statement differs from Java in that it does not; End. The

For details about the if, when, and while statements of kotlin, kotlinwhileIntroduction Kotlin andLike Java, they all have their own process control statements, such as branch statements, loop statements, and jump statements. The difference between the two is not great,Relative to kotlinJava Process Control statements are more flexible and powerful. if If-else statement, representingIf conditions are met,

Kotlin operator overload: add standard operations to any class (KAD 17), kotlinkad By Antonio Leiva Time: Mar 21,201 7 Link: https://antonioleiva.com/operator-overload-kotlin/ Like other languages, some operators have been predefined in Kotlin to perform certain operations. The most typical examples are addition (+), subtraction (-), multiplication (*), Divisi

Use of the when expression in Kotlin: super powerful switch (KAD 13) and kotlinkad By Antonio Leiva Time: Feb 23,201 7 Link: https://antonioleiva.com/when-expression-kotlin/ In Java (especially Java 6), switch expressions have many restrictions. Except for the short type, it basically cannot do anything else. However, the when expression in Kotlin can do ever

Kotlin is a concise encapsulation of Java and provides a lot of convenient syntaxes. After skilled use, it will greatly reduce the number of lines of code and increase the encoding speed.For details about the advantages and disadvantages of kotlin, there are a lot of comments on the Internet. If you are interested, let's start our simple demo development.Requirement: the simplest crud for users, providing r

Antonio LeivaTime:Mar 9,Original link:https://antonioleiva.com/dialogs-android-anko-kotlin/with Builder, creating warning tips and dialogs on Android is relatively simple, but because of the complexity of the language, some hints often become very vague. in the in Kotlin, only Lambda Expressions can help us understand a little bit about how the code is handled. However, with the Anko, we can make it

Kotlin plugin contains an interesting feature that can turn Java code into Kotlin code.So we use it in the Mainactivity.java class. Open the file, and then select Code-> Convert Java file to Kotlin file. The difference between them will make you more familiar with the language. CTRL + SHIFT + A shortcut key input convert Java file to

function Kotlin, a function is defined using the Fun keyword, and the function parameter is defined by the Pascal notation, which is name:type. Parameters are separated by commas. Each parameter must have an explicit type. Fun foo (arg1:string,arg2:boolean,arg3:int): int{ //do somethong return 1 } When a function has only a single expression, you can omit the curly braces, write directly after =, or omit the return value type if the return va

Arc Menu 2 (animation fade-in +kotlin development)Preface: A curved menu based on Androidstudio, which is developed using the Kotlin language, and the animation is gradually entered ...Effect:Development environment: androidstudio2.2.1+gradle-2.14.1Knowledge Involved: 1. Custom controls, 2. Event distribution, etc.Part of the code:Activity:classhomepageactivity:appcompatactivity () {Privatevar homepagemenul

Keywords in kotlin that are consistent with Java usage include: override, while declarations · Open in Kotlin a class needs to be inherited by another class, you need to use the Open keyword Open Class Openclass {} · is judgment type Fun testis () { var a:any? = null; A = 3L if (A is int) { println (' A is int ') } else if (A is long) { println ('

Kotlin recently is a fire, so want to try, of course, IntelliJ is very useful, but open a bit slow, for me this just touch kotlin small white ... (I was impatient 0.0.) So think or try to be able to use sublime text directly compiled run, words not much to say, directly on dry: I have already installed the Java environment by default. 1. The first step is to download ko