13次作业

 

package 字符串;

import java.util.*;

public class 电子邮箱 {

    public static void main(String[] args) {
        String regex = "[a-zA-Z]*+[0-9]{6,20}+@{1}+((163){1}|(qq){1}|(sina){1})+.{1}+com{1}";
        Scanner a = new Scanner(System.in);
        System.out.println("请输入邮箱");
        String s1 = a.next();
        if (s1.matches(regex))
            System.out.println("这个邮箱合法");
        else
            System.out.println("这个邮箱不合法");

    }
}