public class HelloWorld{
public static void main(String[] args){
int num = 999;
int count=0;
switch(num/10)
{
    case 0:
        System.out.println("它是个1位的数!");break;
    case 1:
        System.out.println("它是个2位的数!");break;
    case 2:
        System.out.println("它是个3位的数!");break;
    case 3:
        System.out.println("它是个4位的数!");break;
    case 4:
        System.out.println("它是个5位的数!");break;
    case 5:
        System.out.println("它是个6位的数!");break;
    case 6:
        System.out.println("它是个7位的数!");break;
    case 7:
        System.out.println("它是个8位的数!");break;
    case 9:
        System.out.println("它是个9位的数!");break;
   
}

}
}