确定字符串中的数字和字母数

Question

import java.util.Scanner;

public class digitthingy
{
    public static void main(String args[])
    {
        Scanner s = new Scanner(System.in);

        String first="";
        int firstnum=0;

        System.out.print("Enter a string: ");
        first = s.nextLine();

        firstnum = first.indexOf("1-100");

        System.out.println(firstnum);
    }
}

我想知道我输入的某个字符串中有多少个数字,但我不知道该怎么做.我是编程新手.

Answer 1

这看起来像是一份工作regular expressions!

String s = "sdf234sdf234";

System.out.println(s.replaceAll("\\D", "").length());

或者也许你的每个多位数字实例之后？

String s = "sdf234sdf234sdf23";

s = s.replaceAll("^\\D+|\\D+$", "").replaceAll("\\D+", ",");

List<String> numbers = Arrays.asList(s.split(","));

System.out.println(numbers);