随笔分类 - Kotlin
摘要：Let's see following code: println(colors.reduce { acc, curr -> "$acc, $curr" }) // red, blue, green, black val myMap = mapOf(1 to "one", 2 to "two", 3
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摘要：In kotlin, "fold" is same in Javascript's reduce. "fold" has initial value "reduce" in kotlin, you don't give initial value val colors = listOf("red",
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摘要：Java way: package com.rsk.java; import java.util.function.Function; public class FPExample { public static Function<String, String> toSentenceCase = x
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摘要：For example you have the Java class: package com.rsk.java; import com.rsk.kotlin.Customer; import com.rsk.kotlin.CustomerDatabase; import java.util.*;
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摘要：buildscript { ext.kotlin_version = '1.1-M01' ext.kotlin_gradle_version = '1.1-M01' ext.mokito_kotlin_version = '0.6.0' ext.spek_version = '1.0.89' ext
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摘要：Create a Kotlin class: package com.rsk.kotlin class Meeting(val title: String) { // in Java, you can use getLocation and setLocation var location = ""
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摘要：Create a Java class: package com.rsk.java; import org.jetbrains.annotations.Nullable; public class Person { private String name; private int age; priv
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摘要：package com.rsk interface Signatory { fun sign() } open class Person(val name: String, var age: Int, var isMarried: Boolean = false): Signatory { over
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摘要：If your method is just a single line, it is good to use method expressions: interface Signatory { fun sign() } class Person: Signatory { override fun
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摘要：In Kotlin, there is no static methods, but we can use companion object which works the same as static methods. For example, a class: package com.rsk i
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摘要：First version: fun main(args: Array<String>) { val providers = Providers() val details = providers.getAllProviders() details.forEach { detail -> print
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摘要：fun getAllProviders(fn: (String, String) -> Unit) { // Unit is just like void val allProviders = Providers.getProviders() val it = allProviders.iterat
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摘要：fun main(args: Array<String>) { val ipToCount = mutableMapOf<String, Int>() File("src/ips.txt").forEachLine { val previous = ipToCount.getOrDefault(it
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摘要：fun main(args: Array<String>) { val namesToAges = mapOf(Pair("Peter", 24), Pair("Roger", 42)) val namesToAges2 = mapOf( "Peter" to 24, "Roger" to 42 )
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摘要：import java.io.File fun main(args: Array<String>) { File("src/inputFile.txt").forEachLine { print(it) // it refers to each line's content } }
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摘要：var letters = str.toLowerCase().toCharArray().toHashSet()
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摘要：import java.util.* fun main(args: Array<String>) { val number = Random().nextInt(100) + 1 var input: String? var guess = -1 while(guess!=number) { pri
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摘要：//vararg: just like ...args in js class Stack<T>(vararg val items: T) { val elements = items.toMutableList() fun push(element: T) { elements.add(eleme
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摘要：//vararg: just like ...args in js class Stack<T>(vararg val items: T) { val elements = items.toMutableList() fun push(element: T) { elements.add(eleme
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摘要：private protected internal: accessable for the project / module public https://kotlinlang.org/docs/reference/visibility-modifiers.html
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