Java Basic(38)-Public, Private and this

public class tuna { →它在任何class可以使用

private int hour = 1;

private int minute = 2; → private 只可以在這個class使用

private int second = 3;

public void setTime(int hour, int minute, int second){ →這裡是用private

hour = 4;

minute = 5;

second = 6;

}

public String toMilitary(){

return String.format("%02d:%02d:%02d", hour,minute,second);

}

public String toString(){

return String.format("%d:%02d:%02d %s", ((hour==0||hour==12)?12:hour%12), minute, second,(hour < 12? "AM":"PM"));

}

}

不改變任何apples.java，然後運行它：

01:02:03

1:02:03 AM

01:02:03

1:02:03 AM

但如果你改變：

public void setTime(int hour, int minute, int second){

this.hour = 4;

this.minute = 5;  →這意味著不使用private

this.second = 6;

}

因此，再次運行程序，你會看到：

01:02:03

1:02:03 AM

04:05:06

4:05:06 AM