这个邮箱对应的qq

import java.util.Scanner;

public class Mailbox {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("输入QQ邮箱：");
String qqMail = sc.next();
int index = qqMail.indexOf('@');
String qqNum = qqMail.substring(0, index);
System.out.println("这个邮箱对应的qq：" + qqNum + "。");
sc.close();
}
}