2.26

package random;
//随机输入一个11位数的电话号码
//第一位是1 第二位是不小于3的数字
import java.util.Random;

public class RandomNum {
    public static void main(String[] args) {
        Random rand = new Random();
        System.err.println("随机生成的九个11位的电话号码是：");
        for(int i = 0;i<11;i++) {
            do {
                int num = rand.nextInt(2);
                if(num == 1) {
                    System.out.print(num);
                    break;
                }
            }while(true);
            do {
                int num = rand.nextInt(10);
                if(num >= 3) {
                    System.out.print(num);
                    break;
                }
            }while(true);
            for(int j = 0;j<9;j++) {
                int num = rand.nextInt(10);
                System.out.print(num);
            }
            System.out.println();
        }
        
        
        
        
        
    }
}

package random;

import java.util.Random;

import javax.swing.text.AbstractDocument.Content;

//随机生成6位验证码
public class RandomYzm {
    public static void main(String[] args) {
        Random ran = new Random();
        System.out.print("随机的6位验证码是：");
        for(int j = 0;j<6;j++) {
            do {
                int num = ran.nextInt(150);
                if(num>64&&num<91) {
                    char ch = (char)num;
                    System.out.print(ch);
                    break;
                }
                if(num>96&&num<123) {
                    char ch = (char)num;
                    System.out.print(ch);
                    break;
                }
                if(num<10) {
                    System.out.print(num);
                    break;
                }
            }while(true);

        }
    }
}