尝试从 cs50 编译 pset2 的可读性 .. 给出相同的错误“使用未声明的标识符”将不胜感激任何建议

Question

试图从 cs50 编译 pset2 的可读性。不知道出了什么问题。 向我展示了很多错误。 我试图修复它们，但它给出了新的。 开始认为问题可能完全不同。 所以我被卡住了，找不到解决方法。 将不胜感激任何帮助！ 谢谢！

    int main(void)
      {
      string text = get_string("Text:");
      int letterCount = 0;
      int wordCount = 0;
      int sentCount = 0;
      for(int n = 0; len = strlen(text); n < len; n++)
      {
        if(isalpha(text[n]))
           letterCount++;
        if ((n == 0 && text[n] != ' ') || (n != len - 1 && s[n] == ' ' && s[n +1] != ' '))
           wordCount++;
        if ((text[n] == '!') || (text[n] == '.') || (text[n] == '?'))
           sentCount++;
      }

      //Average number of letters per 100 words
      float avLetters = (letterCount / (float) wordCount) * 100;
      //Average number sentences per 100 words
      float avSent = (sentCount  / (float) wordCount) * 100;
    // find the index
    int Grade = round(0.0588 * avLetters  - 0.296 * avSent - 15.8);

      if(Grade < 16)
           printf("Grade %i\n", Grade);
      else if ( Grade >= 16)
           printf("Grade 16+");
      else
           printf("Before Grade 1");

}



Readability.c:12:18: error: use of undeclared identifier 'len'
  for(int n = 0; len = strlen(text); n < len; n++)
                 ^
Readability.c:12:42: error: use of undeclared identifier 'len'
  for(int n = 0; len = strlen(text); n < len; n++)
                                         ^
Readability.c:12:45: error: expected ')'
  for(int n = 0; len = strlen(text); n < len; n++)
                                            ^
Readability.c:12:6: note: to match this '('
  for(int n = 0; len = strlen(text); n < len; n++)
     ^
Readability.c:12:47: error: use of undeclared identifier 'n'
  for(int n = 0; len = strlen(text); n < len; n++)

            ^

Answer 1

我修复了您的编译错误，您可以将其与您的版本进行比较，看看出了什么问题。 这是构建和运行固定代码的链接。

#include<cs50.h>

int main(void) {
  string text = get_string("Text:");
  int letterCount = 0;
  int wordCount = 0;
  int sentCount = 0;
  for (int n = 0, len = strlen(text); n < len; n++) {
    if (isalpha(text[n]))
      letterCount++;
    if ((n == 0 && text[n] != ' ') ||
        (n != len - 1 && text[n] == ' ' && text[n + 1] != ' '))
      wordCount++;
    if ((text[n] == '!') || (text[n] == '.') || (text[n] == '?'))
      sentCount++;
  }

  // Average number of letters per 100 words
  float avLetters = (letterCount / (float)wordCount) * 100;
  // Average number sentences per 100 words
  float avSent = (sentCount / (float)wordCount) * 100;
  // find the index
  int Grade = round(0.0588 * avLetters - 0.296 * avSent - 15.8);

  if (Grade < 16)
    printf("Grade %i\n", Grade);
  else if (Grade >= 16)
    printf("Grade 16+");
  else
    printf("Before Grade 1");
}