2021-11-30（Kotlin学习笔记）lambda

fun main(){

    //不能调用 01 - 04
    var method01: () -> Unit

    var method02: (Int,Int) -> Int

    var method03: (String,Double) -> Any?

    var method04: (Int,Double,Long,String?) -> Boolean

    //lambda
    var m06 : (Int,Int) -> Int = {num1,num2 -> num1 + num2}
    println("m06:${m06(9,9)}")


    var m07 = { num1: Int,num2: Int -> num1 + num2 }
    println("m07:${m07(1,3)}")

    var m08 : (String,String) -> Unit = {aStr,bStr -> print("a:${aStr},b:$bStr")}
    m08("a","b")

    var m09: (String) -> String = {str -> str }

    var m10 : (Int) -> Unit = {
        when(it){
            1 -> println("你是一")
            in 20..30 -> println("20 to 30")
            else -> println("其他")
        }
    }

    var m11 : (Int,Int,Int) -> Unit = { n1,n2,n3 ->
        println("n1:$n1")
    }

    var m12  = { println("我是M12") }

    var m13 = {sex: Char -> if(sex == 'M') "男" else "女"}
    println("m13:${m13('M')}")
    //覆盖
    var m14 = {num1 : Int -> println("我是m14")}
    m14 = { println("覆盖 $it")}
    m14(99)
    //有返回值
    var m15 = { num: Int -> println("打印${num}")
        num
    }
}