- Java code
public class TV extends Machine{ private String brand; private int maxvolume; public TV() { } public void work(){ System.out.println("Play audio and video meida"); } public String toString(){ return "The power is "+getPower()+"\n"+"The voltage is "+getVoltage()+"\n"+"The current is "+getCurrent()+"\n"+"The type is "+getType()+"\n"+"The brand is "+brand+"\n"+"The maximum volume is "+maxvolume; } public static void main(String[] args) { TV tv=new TV(); System.out.println(tv); }}System.out.println(tv);
为什么可以达到
System.out.println(tv.toString());
的效果？
父类Machine里面没有重写方法
------解决方案--------------------
println（Object o)自动调用类的toString，没有重写的话就是 类名＠hashcode
------解决方案--------------------
这个类中重写了toString方法，来判别对象是否相等。