kotlin constructors

Kotlin (1) Build the Kotlin development environment and kotlin As a programming language, Kotlin has been around for several years, but it is not well-known in China. Since Google announced it as the official Android development language in May, Kotlin has suddenly become po

property. For example: Signature Conflict Sometimes we want a named function in a Kotlin to have another JVM name in the bytecode, the most prominent example being caused by type erasure. These two functions cannot be defined in a class at the same time, because their JVM signatures are the same. If we really want them to use the same name in Kotlin, you can use @JvmName to label one or two of them, a

((var4 2) != 0) { var1 = ","; } if((var4 4) != 0) { var2 = ""; } if((var4 8) != 0) { var3 = ""; } return joinString(var0, var1, var2, var3);}@JvmOverloads@NotNullpublic static final String joinString(@NotNull Collection collection, @NotNull String separator, @NotNull String prefix) { return joinString$default(collection, separator, prefix, (String)null, 8, (Object)null);}@JvmOverloads@NotNullpublic static final String joinString(@NotNull Collection collection, @NotNull Stri

Kotlin is 100% interoperable with Java™and android™ In the previous chapters, we've learned about Kotlin's basic syntax, type systems, generics and collection classes, object-oriented and functional programming, and in the previous chapter we saw the lightweight concurrency programming model provided by Kotlin: the related content of the coprocessor. From the beginning of this chapter to the later chapters,

java. lang. Object. In particular, it has no members except equals (), hashCode (), and toString. For more details, refer to Java interoperability section. To declare an explicit supertype, we put the type after the colon of the Class header: open class Kotlin1{ init { print("first") } constructor(fileName: String, size: Int, age: Int){ print("second") } } class Kotlin2 : Kotlin1("music",20,20) { } The open Annotation on the class is opposite to final i

$name") } } sayhello () //Hello World When you call a function, you can not pass parameters for parameters that already have a default value specified. You do not have to pass parameters in the order in which they are declared, but you must specify the name of the parameter to pass (the parameter is named for the function), and with this feature you can reduce the number of overloaded functions, such as the above function SayHello can be called as follows: SayHello (times = 2, name = "K

Directory Introduction website and document Chinese Community Tutorials Articles Open Source Library and framework Demo Other introduction Why do this. On Google I/O this morning, Google officially announced official support for Kotlin. In order to let everyone faster understanding and hands-on Kotlin, here for everyone to tidy up this kotlin resources, hope can

Kotlin data class: saves a lot of lines of code (KAD 10) and kotlin many lines By Antonio Leiva Time: Jan 25,201 7 Link: https://antonioleiva.com/data-classes-kotlin/ In the previous article, we have seen classes, and data classes can further help us simplify code. What is a data class? DataIs an action that only contains the status and does not have any exec

use them in Kotlin. The Kotlin team is committed to resolving (https://youtrack.jetbrains.com/issue/KT-2095) in the M11 release. Update: Kotlin M11 was released and includes an auxiliary constructor (http://kotlinlang.org/docs/reference/classes.html#constructors). Android JUnit test for the project : The

Use Kotlin to develop Android and kotlin to develop android Check out all my open-source projects [open-source lab]Welcome to my QQ group: [201055521]. Please click to download the source code of this blog client]Summary I first declared that I didn't use Kotlin for a long time. I wrote these articles almost simultaneously. I didn't try any other alternative lan

In this article we will learn the basic syntax and common operation Basic types of Kotlin by analogy with Java syntax Java Kotlin bit width Double Double 64 Float Float 32 Long Long 64 Int Int 32 Short Short 16 Byte Byte 8 Note: Char is not a basic data

KOTLIN development language documentation (official documentation), kotlin development language Web link: https://kotlinlang.org/docs/reference/basic-types.html2. Basic Concepts 2.1. Basic Types From the perspective of Calling member functions and attributes in any variable processing, everything in the Kotlin development language is an object. Some types are emb

Kotlin series: top-level functions and attributes, top-level functions of kotlin Series Let's take a look at top-level functions and attributes in Kotlin today.Problems encountered As we all know, in Java, all codes exist based on classes. Our so-called Functions Act as class methods, and our so-called attributes act as class attributes. However, in some cases,

Kotlin series exceptions and Kotlin Series Issues In this section, we will talk about exceptions in Kotlin.Java exceptions We know that exceptions in Java are an endless topic. When talking about exceptions, the first thing that comes to mind isTry... catch... finally is the same in Kotlin. The usage is almost unchanged, but there are also some small changes. He

How to convert code from Java to Kotlin: Now you can use Kotlin (KAD 29) and kotlinkad By Antonio Leiva Time: Jul, 4, 2017 Link: https://antonioleiva.com/kotlin-from-java/ One of the most amazing features of Kotlin is its ability to fully integrate with Java. This means that although all the code of your application

The first kotlin project and the first kotlin Project How to Use Kotlin in Android Studio? 1. Use the Android Studio plug-in 2. Upgrade Android Studio to version 3.0: it is not recommended currently, because version 3.0 is still in the Dev Channel, that is, the development Channel, and has not yet been officially released. So today we will talk about how to creat

The path to kotlin growth and the path to kotlin Learning Preface: Starting from Kotlin, that is, my decision to start writing a technical blog today, I have a poor literary talent. Thank you for your understanding and guidance. This article is my guide to Kotlin growth for the most bloggers. Therefore, the content i

Introduction to Kotlin syntax and kotlin syntaxKotlin syntax Kotlin is toxic and addictive when used ...... A little exaggerated. It was actually used to write a demo that records POI and tracks. However, the syntax is really concise. Here, Kotlin is different from Java, or it has more concise and elegant syntax and fe

Kotlin series: extended functions and attributes, and kotlin series extended functions Extended functions and attributes can be added based on existing classes, but these functions and attributes are defined outside the class. Are you curious? Let's take a look.Extended Functions Let's use an example to analyze and add a member function to the String class.LastChar, used to obtain the last character of a s

inheritance by default, you must use the Open keyword to represent inheritable, 2, swift defaults to support inheritance, 3, Kotlin use Contructor to define constructs function, which is divided into primary and secondary constructors, the secondary constructor must call the primary constructor, 4, Kotlin uses this to invoke other