求教!还是类的问题,请多多指教. 声明一个CAT类,拥有类的变量HowManyCats,记录cat的个体数目.类方法GetHowMany(),存取HowManyCats,设计程序测试这个类,体会类变量与类方法的用法. 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 哥们, 这个就自己写下吧使用一个static域就可以了 class Cat { private int howManyCats; public Cat(int catsNum) { this.howManyCats = catsNum; } public int getHowMany() { return this.howManyCats; }}class TestCats{ public static void main(String[] args) { Cat cat = new Cat(5); System.out.println("cat number: " + cat.getHowMany()); }} 拥有类的变量和类的方法。所以HowManyCats和getHowMany() 方法应该是static的。class Cat { public static int howManyCats = 0; public static int getHowMany() { return howManyCats; } public void setCatNum(int catNum){ howManyCats = catNum; }}只需记住,静态的对象和方法不基于对象而基于类。测试如下:class TestCats{ public static void main(String[] args) { Cat cat1 = new Cat(); Cat cat2 = new Cat(); System.out.println("cat1 number: " + cat1.getHowMany()); System.out.println("cat2 number: " + cat2.getHowMany()); cat2.setCatNum(10); System.out.println("cat1 number: " + cat1.getHowMany()); System.out.println("cat2 number: " + cat2.getHowMany()); }}结果为001010 class Cat { public static int howManyCats = 0; public Cat(){ howManyCats++; } public static int getHowMany() { return howManyCats; } public void setCatNum(int catNum){ howManyCats = catNum; }} 这几个题目我吃不准 Swap 函数问题 关于用java 6 登陆校内网 关于java 大家看下! 新手做这样一个程序需要多长时间? 如果在JFrame里调用JPanel里的KeyListener事件. 简单问题,跪求答案! java直接连接sqlserver时出现的问题 jdbc驱动程序的问题? 这个算法如何用java实现? 如何给 JTable 的列之间 的那个线加上事件???
private int howManyCats; public Cat(int catsNum) {
this.howManyCats = catsNum;
} public int getHowMany() {
return this.howManyCats;
}}class TestCats{
public static void main(String[] args) {
Cat cat = new Cat(5);
System.out.println("cat number: " + cat.getHowMany());
}}
return howManyCats;
} public void setCatNum(int catNum){
howManyCats = catNum;
}}只需记住,静态的对象和方法不基于对象而基于类。测试如下:class TestCats{
public static void main(String[] args) {
Cat cat1 = new Cat();
Cat cat2 = new Cat();
System.out.println("cat1 number: " + cat1.getHowMany());
System.out.println("cat2 number: " + cat2.getHowMany());
cat2.setCatNum(10);
System.out.println("cat1 number: " + cat1.getHowMany());
System.out.println("cat2 number: " + cat2.getHowMany());
}
}结果为
0
0
10
10
public static int howManyCats = 0;
public Cat(){
howManyCats++;
} public static int getHowMany() {
return howManyCats;
} public void setCatNum(int catNum){
howManyCats = catNum;
}}