best kotlin tutorial

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,

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

--- [ restartedMain] com.ysl.jna.jna.JnaApplicationKt : Started JnaApplicationKt in 7.447 seconds (JVM running for 8.208)Indicates that your app has started successfully; the second-to-last line of debugging information is as follows:2017-12-23 13:30:39.642 INFO 6788 --- [ restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8080 (http) with context path ‘‘You will see spring boot help you launch Tomcat, (you installed spring boot, he comes with you a

implemented by using functions as parameters, some cannot be called syntax, but functions are nested, infix function call,lambda, function parameters, variable argument lists, flexible tags, powerful return, automatic type judgments, Range,iterator, operator overloading, omitting, template ... These are too many features that cause Kotlin's syntax to dazzle, though sometimes it may seem elegant, but it can also cause great difficulty in reading the code.End this article with a piece of code wit

These days have been preparing for the exam, really no time, has passed so long, finally to the object-oriented!Let's see what the Kotlin in the class look like.Can see Kotlin in the class is still very common, mostly similar to Java, the more special are:Each constructor must have an initial value assigned to each member variable.Primary constructor, the head of this constructor is immediately following th

own inner classes, such as:Back in the message class, we can see that there are also get and set under the info and what fields, well, this is the getter and setter functions, the general Getter function using the default is good, the setter function is actually at the time of assignment to do some processing, To prevent the setter function from infinitely recursive calls, you can use the $ symbol to access member variables in a class, bypassing getter and setter functions to directly access me

Kotlin's control flow is the same as in other languages, order, branching, loopingThere are two types of branching, if-else and when (similar to switch in Java).If statement:Operation Result:The case statement in Java not only supports integer values, the latest JVM also supports strings, kotlin when statements are more powerful, switch variables can even be various types such as Double,array, in other words when statements are more powerful than swit

Directory Introductory video tutorials for Kotlin minimalist tutorials Kotlin System entry to advanced Kotlin from getting started to abandoning Kotlin from zero to Advanced 1th Chapter Kotlin Introduction 2nd Chapter Quick Start: HelloWorld 2nd Chapter Quick Start: Springbo

Original link: Https://github.com/EasyKotlin In the common concurrency model, multi-process, multi-threading, and distributed are the most common, but in recent years there are some languages that provide support for the concurrent-based concurrency model in the form of first-class or library. Some of the more typical scheme, Lua, Python, Perl, go and so on in the first-class way to provide support for the co-process. Similarly, Kotlin also supports t

Annotation definition Annotations Annotation Class Fancy constructor for annotations can take parameters Annotation Class Special (Val why:string) Special ("Example") class Foo {} using Annotations @fancy class Foo { @fancy fun baz (@fancy foo:int): Int { return 1 } } annotations in the main constructor Class Foo @inject Constructor (dependency:mydependency) annotations in property visitors Class Foo { var x:mydependency?=null @inject Set } annotations in

Packages A source file typically starts with a definition package Package Com.doctorq.packages Fun Main (args:array Note that this place is not directly related to the directory where the package name and source files are located, and the compiled file will install the defined package name to generate the appropriate directory Default imported Package kotlin.* kotlin.annotation.* kotlin.collections.* kotlin.comparisons.* (since 1.1) kotlin.io.* k

NULL security An important feature of the Kotlin system is its commitment to eliminate null references. Avoid any NPE (nullpointerexception) exceptions. Defining a variable that is allowed to be empty in Kotlin is not allowed to be defined in an empty way. var a:string = "ABC"//Cannot be an empty var b:string? = "ABC"//Can be empty b.length//may error //second one more than the first one '? ' Null valu

Returns and Jumps Like Java, there are 3 jump statements in Kotlin return break continue break and Continue tags We can give an alias to any expression, Kotlin call this a label. Take an example of the previous for Loop statement Doctorq@for (index in array.indices) { println (index) } I've added a label to this for loop, with a suffix of @ doctorq@ for (i-1..100) { doctorq2@ for (J-in

Control Flow If expression In Kotlin, if is an expression that has a return value. But does not support three mesh operations Val A = 1 val b = 2 var max = a if (a If the if branch is a block of code, the last expression of the code block defaults to the return value Val max4 = if (a > B) { print ("Choose a") a } else { print ("Choose B") b } If an if expression returns a result or if an if expres

As you can see, the function definition isfunction body}Single-statement functions can be abbreviated, such as the Add function and the ADD1 function are the same effectVariable definitionvar Constant definitionVal Constants and variables can have no initialization values, but must be initialized before referencing them.The compiler supports automatic type judgments, which can be declared without specifying a type, which is judged by the compilerOperation Result:Kotlin Chinese

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

successfully adopted by a number of major companies, some of which share their experience: Pinterest has successfully introduced Kotlin into their applications, with 150 million people per month. Basecamp's Android app is 100% Kotlin code, they report huge differences in programmer happiness, as well as a huge improvement in quality and speed of work. Keepsafe's app Lock application has al

first, class definition The class is declared using the Generic keyword class in Kotlin, followed by the class name: Class Kotlinclass {// class name Kotlinclass //curly braces are the body composition } Interface Definition Interface Ikotlininterface Single Case Kotlin uses the object class to modify classes, you can implement a singleton mode,Java Singleton class: public class javainstanceclass{

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