c - 如何在C中合并文本中的所有可能空格

Question

该函数的目的是将字符串中所有可能的空格合并到一个空格中。我编写的代码可以正常工作，但有一个字符串会中断。

void merge_whitespace(char *str) {
     char *d = str;

  while(*str != '\0') {
        while (*str == '\t' || *str == '\r' || *str == '\n' || *str =='\f' || *str =='\v' || (*str == ' ' && *(str+1) == ' ')) {
          str++;
        }
      *d++ = *str++;
  }
    *d = '\0';
 }   


test
[This  is another test.     Now we 

 have all kinds of    white space   ]

My output is:
[This is another test. Now we  have all kinds of white space ]


but should be:

[This is another test. Now we have all kinds of white space ]

So the problem is in the string test, it prints two spaces instead of one.

标签： cpointerswhitespace

Answer 1

文字就像

" \n "

因此，当遇到第一个空格时，它会检查

(*str == ' ' && *(str+1) == ' ')

str 确实等于 ' '，但 str+1 等于 '\n'，而不是 ' '。所以，这就是它失败的方式。