小编SK.*_*hen的帖子

我试过如下代码

 val a: Int? = 1024
 println(a is Int) // true
 println(a is Int?) // true
 println(a is String) // **error: incompatible types: Long and Int? why the value cannot be checked with any type?**

但这很有效：

fun checkType(x: Any?) {
    when(x) {
        is Int -> ...
        is String -> ... // **It works well here**
        else -> ...
    }
}