C、字符数组，错误: subscripted value is neither array nor pointer nor vector?

Question

我是编写代码的新手，所以请简要解释您的答案，以便我可以(尝试)跟上，谢谢!我正在尝试输入一个字符串，将该字符串分配给一个字符数组，并有选择地提取所述字符字符串的一部分以返回(即输入“字符”并返回“行为”)，我似乎无法理解为什么我不断收到错误“下标值既不是数组也不是指针也不是 vector ”。这是我的代码:

 #include <stdio.h>

    char source[81], result[81];
    int start, count;

    char substring ();

    int main(void) 
    {
        substring ("character", 4, 3, result);
        printf ("%s", result); //print result
        return 0;
    }

    char substring (source, start, count, result)
    {
        int i = 0;
        while (i <= (count-1))
        {
            result[i] = source[((start-1)+i)]; //op chosen chars to result array
            ++i;
            if (i == count)
            {
                result[i] = '\n'; //when i = count, insert null at end of source array
            }
        }
        return result;
    }

当我尝试编译时，出现错误:”

Compilation error    time: 0 memory: 0 signal:0
prog.c: In function ‘substring’:
prog.c:20:13: error: subscripted value is neither array nor pointer nor vector
       result[i] = source[((start-1)+i)]; //op chosen chars to result array
             ^
prog.c:20:25: error: subscripted value is neither array nor pointer nor vector
       result[i] = source[((start-1)+i)]; //op chosen chars to result array
                         ^
prog.c:24:14: error: subscripted value is neither array nor pointer nor vector
        result[i] = '\n'; //when i = count, insert null at end of source array
              ^"

Answer 1

您应该为 substring() 的参数声明显式类型:

char substring(char* source, int start, int count, char* result)