[移动开发]Kotlin 基本语法

1. 函数定义

fun main(a: Int, s: String): Int{
	val a = 1
	println("a = ${a}"
	return a
}

主函数 main，关键字 fun，: 后跟返回的类型，${val}字符串模板取对应值。val 定义常量，var 定义变量

2. 基本类型

a: Int
s: String
number: IntRange 数值范围类型，如：val diceRange = 1…6

3. 创建类

var dice = Dice(6)

class Dice(val numSides: Int){
    fun roll(): Int{
        return (1..numSides).random()
    }
}

外部可直接调用dice.numSides获得实例化的参数

4. 条件语句

val num = 4
if (num > 4) {
	println("The variable is greater than 4")
} else if (num == 4) {
	println("The variable is equal to 4")
} else {
	println("The variable is less than 4")
}

val luckyNumber = 4
when (rollResult) {
   luckyNumber -> println("You won!")
   1 -> println("So sorry! You rolled a 1. Try again!")
   2 -> println("Sadly, you rolled a 2. Try again!")
   ...
   else -> println("Else Situation")
}

when: rollResult 和 ->前面的值比较