package cn.test;
import java.util.ArrayList;
import java.util.Vector;
public class TestMain {
    public static void main(String[] args) {
        Object testObject = new ArrayList();
        displayObjectClass(testObject);
        displayString("字");
    }
    public static void displayObjectClass(Object o) {
        if (o instanceof Vector)
            System.out.println("对象是 java.util.Vector 类的实例");
        else if (o instanceof ArrayList)
            System.out.println("对象是 java.util.ArrayList 类的实例");
        else
            System.out.println("对象是 " + o.getClass() + " 类的实例");
    }
    public static void displayString(String str){
        if (str instanceof String)
            System.out.println("是String类的实例");
    }
}