第十三章，枚举与泛型例题-编程知识

第十三章，枚举与泛型例题

例题1

package 例题;interface SeasonInterface{//四季接口int SPRING = 1, SUMMER = 2, AUTUMN = 3, WINTER = 4;
}enum SeasonEnum{//四季枚举SPRING,SUMMER,AUTUMN,WINTER
}public class 例题1 {//定义方法public static void printSeason1(int season){switch (season) {case SeasonInterface.SPRING:System.out.println("这是春季");break;case SeasonInterface.SUMMER :System.out.println("这是夏季");break;case SeasonInterface.AUTUMN :System.out.println("这是秋季");break;case SeasonInterface.WINTER :System.out.println("这是冬季");break;default:System.out.println("这不是四季常量值");break;}}public static void printSeason2(SeasonEnum season){switch (season) {case SPRING:System.out.println("这是春季");break;case SUMMER :System.out.println("这是夏季");break;case AUTUMN :System.out.println("这是秋季");break;case WINTER :System.out.println("这是冬季");break;}}public static void main(String[] args) {//使用接口常量做参数printSeason1(SeasonInterface.SPRING);//使用数字做参数printSeason1(3);//使用接口常量值以外的数字冒充常量值printSeason1(-1);//使用枚举做参数printSeason2(SeasonEnum.WINTER);}
}

结果

例题2

package 例题;//定义枚举
enum Season{SPRING, SUMMER, AUTUMN, WINTER
}public class 例题2 {public static void main(String[] args) {// TODO Auto-generated method stub//使用枚举方法valuesSeason se[] = Season.values();for(int i = 0; i < se.length; i++) {System.out.println("枚举常量：" + se[i]);}}}

结果

例题3

package 例题;enum Season8 {SPRING, SUMMER, AUTUMN, WINTER
}public class 例题3 {public static void main(String[] args) {// TODO Auto-generated method stubSeason8 se = Season8.valueOf("SUMMER");//根据字符串创建一个枚举值Season8 se1[] = Season8.values();//获取所有枚举值for(int i = 0; i<se1.length;i++ ) {String message = "";//待输出消息int result = se.compareTo(se1[i]);//记录两个枚举比较的结果if(result  < 0) {message = se + "在" + se1[i] + "的前" + (-result) + "个位置";}else if(result>0) {message = se + "在" + se1[i] + "的后" + (result) + "个位置";}else if(result==0) {message = se + "与" + se1[i] + "是同一个值" ;}System.out.println(message);}}}

结果

例题4

package 例题;
enum SE{SPRING, SUMMER, AUTUMN, WINTER
}
public class 例题4 {public static void main(String[] args) {// TODO Auto-generated method stubSE se[] = SE.values();for(int i = 0; i < se.length; i++) {System.out.println(se[i] + "在枚举类型中位置索引值" + se[i].ordinal());}}}

结果

例题5

package 例题;
enum Seaon{SPRING("万物复苏"),SUMMER("烈日炎炎"),AUTUMN("秋草枯黄"),WINTER("白雪皑皑");public String remarks;//枚举的备注private Seaon(String remarks) {//构造方法this.remarks = "我是" + this.toString() + "我来之后" + remarks + "。";}public String getRemarks() {//获取备注方法return remarks;}
}
public class 例题5 {public static void main(String[] args) {// TODO Auto-generated method stubSeaon ss[] = Seaon.values();for(int i = 0; i < ss.length; i++) {System.out.println(ss[i].getRemarks());}}}

结果

例题6

package 例题;public class 例题6<T> {private T bookinfo;public 例题6(T bookinfo) {this.bookinfo = bookinfo;}public 例题6() {// TODO Auto-generated constructor stub}public T getBookinfo() {return bookinfo;}public static void main(String[] args) {//创建参数String类型的书名对象例题6<String> bookName = new 例题6("Java从入门到精通");
//		创建参数String类型的作者对象例题6<String> bookAuthor = new 例题6("明日科技");//创建参数String类型的价格对象例题6<Double> bookPrice = new 例题6(69.8);//创建参数String类型的附赠源码例题6<Boolean> hasSource = new 例题6(true);System.out.println("书名：" + bookName.getBookinfo());System.out.println("作者：" + bookAuthor.getBookinfo());System.out.println("价格：" + bookPrice.getBookinfo());System.out.println("是否附赠源码：" + hasSource.getBookinfo());}}

结果

例题7

package 例题;public class 例题7<A> {private A[] array;public A[] getarray() {return array;}public void setArry(A[] array) {this.array = array;}public static void main(String[] args) {例题7<String> dome = new 例题7();String value[] = {"成员1", "成员2", "成员3", "成员4", "成员5"};dome.setArry(value);String array[] = dome.getarray();for(int i = 0; i < array.length; i++) {System.out.println(array[i]);}}}

结果

例题8

package 例题;
import java.util.*;public class 例题8 {public static void main(String[] args) {//定义ArrayList容器，设置容器内是的值为IntegerArrayList<Integer> a = new ArrayList<Integer>();a.add(1);for(int i = 0; i<a.size(); i++) {//根据容器长度，循环显示容器内的值System.out.println("获取ArrayList容器成员的值：" + a.get(i));}//定义HashMap容器，设置容器的键名与键值类型分别为Integer型与String型HashMap<Integer ,String> m = new HashMap<Integer ,String>();for(int i = 0; i<5; i++) {m.put(i, "成员" + i);}for(int i = 0; i<m.size(); i++) {System.out.println("获取Map容器成员的值;"  + m.get(i));}}}

结果