(新手)JAVA 能限制输入者输入的格式吗?

import java.util.*;

public class test{
public static void main (String[] arg) {
Scanner scan = new Scanner(System.in);
String x;
System.out.println(" Please input ");
x = scan.nextLine();

问题这边来了.. 如果我想限制user只能输入数字及dollar sign e.g($100 or $200) 如果有其他不明字符及英文字可以System.out.println(" Input error!");
应该点样做 希望有人帮到手

[ 本帖最后由 傻乂小风 於 2013-12-7 03:08 PM 编辑 ]

you can use "if" function to check the user input.

if you want keep check until user input correct, use "do-while" or "while" function.

I think you don't need use input the the "$", only print out the result then add the "$" into the number is better. Then you can "int", "double", or "float". This can limit user input other than number.
One more reason don't add "$" is if user input like "4$9$38" it will pass the checking, unless your create an array and check every array char.
That will make the program must long and use more memory.

thank you
I try it