Kotlin 学习笔记（持续更新）

基础知识

定义变量(define various)

val name = "None";// 只读
var age = "25";// 可修改

变量类型(various type)

关键字	类型
Byte,Short,Int,Long	整型
UByte,UShort,UInt,ULong	无符号整型
Float,Double	浮点型
String	字符串
Char	字符
Boolean	布尔类型

val name:String = "None";
val age:Int = "25";
val salary:Double = "3000.00";
val male:Char = '♂'

集合(Collection)

关键字	类 型	描述	创建
Array	数组		arrayOf(1,2,3,4)
List	列表	只读	listOf("triangle", "square", "circle")
MutableList	列表	可修改	mutableListOf("triangle", "square", "circle")
Set	set	只读	setOf("apple", "banana", "cherry", "cherry")
MutableSet	set	可修改	mutableSetOf("apple", "banana", "cherry", "cherry")
Map	map	只读	mapOf("apple" to 100, "kiwi" to 190, "orange" to 100)
MutableMap	map	可修改	mutableMapOf("apple" to 100, "kiwi" to 190, "orange" to 100)

流程控制

判断(if,when)

val count = 3;
if(count>3){
    println("count>3")
}else{
    printLn("count<=3")
}

when(count){
    1->println("count ==1")
    2,3->print("count >1")
    else ->print("count>3")
}

循环(for,while)

val numbers = 1..100;
for(a in numbers){
    println(a)
}
var i = 0;
while(i<100){
    print("${numbers.elementAt(i)}\t")
    i++;
}

函数

fun systemPrint(str:String){
    print(str)
}
fun main(){
    systemPrint("Hello Kotlin")
}