JAVA从键盘输入11位手机号码，将第4位-7位替换为“XXXX”并输出替换后的手机号？

Posted 2023-05-08

JAVA，急

参考技术A import java.util.Scanner;
public class test
public static void main(String[] args)
String phoneNum,str="",begin="",end="";
int count = 0;
System.out.print("请输入一个11位手机号：");
phoneNum = new Scanner(System.in).next();
while (phoneNum.length()!=11||(int)(phoneNum.substring(0,1).charAt(0))!=49)
System.out.println("你输入的不是一个11位手机号！\n");
System.out.print("请输入一个11位手机号：");
phoneNum = new Scanner(System.in).next();

for (int i = 0; i < phoneNum.length(); i++)
if ((int)(phoneNum.substring(i,i+1).charAt(0))>=48&&(int)(phoneNum.substring(i,i+1).charAt(0))<=57
)
count++;


while (count!=phoneNum.length())
System.out.println("你输入的不是一个11位手机号！\n");
System.out.print("请输入一个11位手机号：");
phoneNum = new Scanner(System.in).next();

for (int i = 0; i < 3; i++) //截取开头三位
str+=phoneNum.substring(i,i+1);
begin=str;

for (int i = 3; i <= 6; i++) //截取并替换4到7位
str+="X";

for (int i = 7; i < phoneNum.length(); i++) //截取剩余四位
str+=phoneNum.substring(i,i+1);
end+=phoneNum.substring(i,i+1);

System.out.println("你输入的手机号是："+str);
if (begin.equalsIgnoreCase("135")&&end.equalsIgnoreCase("1234"))
System.out.println("恭喜您获得了一等奖！");
else
System.out.println("很遗憾，你未能中奖！");

从键盘上输入输入5个整数到数组,求出数组中的所有偶数，用java语言？

参考技术A public static void main(String[] args)
int a[] = new int[5];
Scanner sc = new Scanner(System.in);
String o = "";
for (int i = 0; i < a.length; i++)
System.out.print("请输入第"+(i+1)+"位整数:");
a[i] = sc.nextInt();//只能录入整数
if (a[i]%2==0)
o+=","+a[i];


System.out.println("偶数为："+o.substring(1));
System.out.println("录入数组为："+Arrays.toString(a));