14.求字符串中的数字字符转化为数字并求和

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string.h>
#include<ctype.h>
int fun(char *s)
{
int sum = 0;
while (*s)
{
if (isdigit(*s))
sum += *s - '0';
s++;
}
return sum;
}
int main()
{
char s[81];
int n;
printf("\nEnter a string :\n\n");
gets(s);
n = fun(s);
printf("\nThe result is: %d\n\n", n);
getchar();
return 0;
}