public class bdtdValues {
    public static void main(String[] args) {

        Variable v = new Variable();
        System.out.println("byte类型的初始值为" + v.byteNum);
        System.out.println("short类型的初始值为" + v.shortNum);
        System.out.println("int类型的初始值为" + v.intNum);
        System.out.println("long类型的初始值为" + v.longNum);
        System.out.println("float类型的初始值为" + v.floatNum);
        System.out.println("double类型的初始值为" + v.doubleNum);
        System.out.println("String类型的初始值为" + v.str);
        System.out.println("boolean类型的初始值为" + v.flag);
        
    }
}
class Variable {
    byte byteNum;
    short shortNum;
    int intNum;
    long longNum;
    float floatNum;
    double doubleNum;
    String str;
    boolean flag;
}

byte类型的初始值为0
short类型的初始值为0
int类型的初始值为0
long类型的初始值为0
float类型的初始值为0.0
double类型的初始值为0.0
String类型的初始值为null
boolean类型的初始值为false