when是什么 when用于在kotlin中实现类c语言中的switch关键字 when怎么用 when (x) { 1 -> print("x == 1") 2 -> print("x == 2") else -> { // Note the block print("x is neither 1 nor 2") } } 差不多是类C语言中这么个意思 swicth(x){ case 1: ....... break; case 2: ....... break; default: // kotlin else ....... break; } 帮助 https://kotlinlang.org/docs/reference/control-flow.html