java中的面向对象的练习
class Book{ private String title; private int ; public Book(){ //无参构造可以作为提示信息;例如: title = "未知"; pageNum = "00"; } public Book(String s1, int s2){ title = s1; pageNum = s2;//此处也可以进行页数判断。 } public String getTitle(){ return title; } public void setTitle(String t){ title = t; } public int getPageNum(){ return pageNum; } public void setPageNum(int n){ if(n<200){ System.out.println("页数不够200"); pageNum = 200; return; } pageNum = n; } public void detail(){ //此处的方法不能用static 如果是则有 静态方法不能访问非静态变量的错误。 //System.out.println(getTitle()); System.out.println(this.title); //System.out.println(getPageNum()); System.out.println(this.pageNum); } } public class Homework{ public static void main(String[] args){ Book one = new Book("fuck", 2510); one.detail(); one.setTitle("fuck you"); one.detail(); one.setPageNum(150); one.detail(); } }