package homework;
import java.util.*;
/**
 * 隨機產生四位驗證碼    0--9，a--z,A--Z隨機取4個數作為驗證碼
提示 a-z 範圍65-90
A-z 範圍97-122
 * @author 雨
 *
 */
public class Homework2 {
public static void main(String[] args){
ArrayList<Object> array=new ArrayList<Object>();
Random rand =new Random();
for(int i=0;i<4;i++){
int choice=rand.nextInt(3);
switch (choice) {
case 0:
int num=rand.nextInt(9);
array.add(num);
break;
case 1:
int num2=rand.nextInt(25)+65;
char low=(char)num2;
array.add(low);
break;
case 2:
int num3=rand.nextInt(25)+97;
char high=(char)num3;
array.add(high);
break;
default:
break;
}
}
System.out.println("你得到的四位驗證碼：");
for (Object object : array) {
System.out.print(object);
}
}

}