Question

我想知道如何确保只输入字符。有任何想法吗？

printf("Enter Customer Name");

scanf("%s",cname);

Answer 1

您可以读取字符串，然后使用isalpha()或类似功能进行扫描。

#include <stdio.h>
#include <string.h>
#include <ctype.h>

#define STR(x) #x
#define SSTR(x) STR(x)
#define STR_FMT(x) "%" SSTR(x) "s"

#define CNAME_MAX_LEN 50

int inputName(char *cname)
{
  size_t i;

  do
  {
    printf("Enter Customer Name: ");
    fflush(stdout);

    if (1 != scanf(STR_FMT(CNAME_MAX_LEN), cname))
      return 1;

    for (i = 0; isalpha(cname[i]); ++i);
  }
  while (i == 0 || cname[i]);

  return 0;
}

int main()
{
  char cname[CNAME_MAX_LEN + 1];

  if (inputName(cname))
  {
    perror("error reading in name!\n");
    return 1;
  }

  printf("cname is '%s'\n", cname);

  return 0;
}

Answer 2

您可以使用strspn()来测试字符串，如下所示：

#include <stdio.h>
#include <string.h>

int main(void){
    char str[100] = {0};
    int len;
    scanf ("%99s", str);
    len = strlen(str);
    if (len != strspn(str, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"))
        printf ("Your string contains non-alphabet characters.\n");
    else
        printf ("Your string is good.\n");
    return 0;
}

在C中只接受字母和整数

2 个答案: