用起来很方便，代码如下

#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int digit (int x){int count = 0;do {count++;x = x / 10;} while (x > 0);	return count;}
int main()
{int x = 0;scanf("%d", &x);int number = digit(x);printf("%d", number);}