c - 检查ISBN在C语言中是否有效

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我正在尝试检查ISBN在C中是否有效。我想忽略不是整数的任何数组值，例如忽略-或空格。以下代码部分出现错误：

if(s[jj] == '-' || size[jj] == ' ')

错误消息如下：


  错误：下标值既不是数组也不是指针

int checkISBN( char s[] ) {
        int result = 0;
        int theSize = 18;  /* Most ISBNs are 10 digits long, with some being
                            * 13. I just chose 18 incase there are a lot of
                            * blank spaces or dashes in the array. */
        int n = 1;         /* This comes in handy for determing if the check
                              character is valid. */
        int sum = 0;       /* We divide this value by 11 to determine if the
                              check character is valid */
        int jj;

        for (jj = 0; jj sum += s[i] * n; ++n;
                /* For the below, the formula works like this:
                 * The sum for the ISBN 0-8065-0959-7 is

                   1*0 + 2*8 + 3*0 + 4*6 + 5*5 + 6*0 + 7*9 + 8*5 + 9*9 = 249

                 * The remainder when 249 is divided by 11 is 7, the last
                 * character in the ISBN. The check character is used to
                 * validate an ISBN.
                 * */
        ...
}

...

int checkCharacter = sum / 11;

if (checkCharacter == s[size-1]) {
        result = 1;
        /* I know this part is wrong.
        * If the array only contains 10 values, then s[17] will be null.
        * I'll fix this later.
        * */
        return result;;
        /* Fix this to return a calculated value based on string */
}

最佳答案

简单的错字，size不是数组。它应该是：

if(s[jj] == '-' || s[jj] == ' ')
                  ^^^

关于c - 检查ISBN在C语言中是否有效，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/21869961/