Kotlin笔记-011分支表达式

分支表达式

if/else 表达式

fun action(){
    var index:Int = 5
    if (index < 10) {
        index = 0
    } else {
        index = 10
    }
}

等价于：

fun action(){
    var index:Int = 5
    index = if (index < 10) {
        0
    } else {
        10
    }
}

when 表达式

// 用于范围判断
fun action(){
    var index: Int = 1
    var x: String = when (index) {
        0 -> "0"
        1 -> "1"
        else -> "null"
    }
}

// 用于类型判断
fun action(){
    var index: Any = "Kotlin"
    var x: Int = when (index) {
        is String -> 0
        is Int -> 1
        else -> 2
    }
}

try/catch 表达式

fun action(){
    var a: Int = 10
    var b:Int = 1

    var c:Int = 0
    c = try {
        a/b
    } catch (e: Exception) {
        println(e.toString())
        0
    }
}