kotlin 测试if表达式、数组等

fun main() {
    val addr : Any = "江苏南京"
    if (addr is String) { // 里面会自动类型转化为String
        println("addr is String, length: " + addr.length)
        for (i in 0..addr.length - 1 step 1) {
        	println(addr[i])
    	}
    }
    val address = addr as? String ?: return // as? 安全的类型转换操作符，转化失败返回null。 ?: return表示转化失败提前退出
    println("address is String, length: " + address.length)
    for (i in 0 until address.length) {
     	println(address[i])
    }
    
    val stringArray: Array<String> = arrayOf("乔丹", "科比","艾弗森", "麦迪", "韦德", "詹姆斯", "杜兰特", "库里", "奥尼尔", "霍华德", "加内特", "兰多夫", "加索尔")
    for (str in stringArray) 
    	println(str)
    
    val idx = 1000
    val obj: Any = if (idx in 0 until stringArray.size) { // if表达式
        println("idx in range")
        "idx in range"
    } else {
        println("idx not in range")
        "idx not in range"
    }
    println("obj: " + obj)
}

打印：

ok .测试了数组，if表达式等