c++ - C++错误: expected primary-expression before ‘}’ token

Question

我试图调用一个名为correction(original,corrected)的void函数，当我尝试对其进行编译时，出现了以下几种错误:

error: expected primary-expression before ‘}’ token

这是我完整的代码:

    #include <cstdio>
    #include <iostream>
    #include <fstream>
    #include <cstdlib>
    #include <string>

    using namespace std;

    void correction(ifstream& original,ofstream& corrected);

    int main ()
    {
      ifstream original;
      ofstream corrected;
      char filename[16];
      cout<<"Enter filename:\n";
      cin>>filename;
      original.open(filename);
      corrected.open("corrected.txt");
      if (original.fail( ))
        {
    cout << "Input file opening failed.\n";
          exit(1);
        }
    if (corrected.fail( ))
      {
        cout << "Input file opening failed.\n";
        exit(1);
      }
     else
       {
         correction(original,corrected);
}
 return 0;
}

void correction(ifstream& original,ofstream& corrected)
{
char symbol;
while(! original.eof())
  {
    original.get(symbol);
    if (symbol== 'c')
{
     corrected.put(symbol);
     original.get(symbol);
     if (symbol=='i')
       {
         corrected.put(symbol);
         original.get(symbol);
         if (symbol=='n')
           {
             corrected.put(symbol);
             original.get(symbol);
while (symbol==' ')
                 {
                   original.get(symbol);
                     }
             for (symbol=='<')
               {
                 corrected.put('>');
                 original.get(symbol);
               }
             corrected.put(symbol);
           }
}
     if (symbol=='o')
       {
         corrected.put(symbol);
         original.get(symbol);
         if (symbol=='u')
           {
             corrected.put(symbol);
             original.get(symbol);
             if (symbol=='t')
               {
                 corrected.put(symbol);
                original.get(symbol);
                 while (symbol==' ')
                   {
                     original.get(symbol);
                   }
                 for (symbol=='>')
                   {
                     corrected.put('<');
                     original.get(symbol);
                   }
                 corrected.put(symbol);
               }
           }
       }
   }
 else
   corrected.put(symbol);
  }
 return;
}

当我尝试编译此代码时，出现以下错误:

operators.cpp:59:23: error: expected ‘;’ before ‘)’ token for (symbol=='<') ^ operators.cpp:65:5: error: expected primary-expression before ‘}’ token } ^ operators.cpp:65:5: error: expected ‘)’ before ‘}’ token > >operators.cpp:65:5: error: expected primary-expression before ‘}’ token operators.cpp:65:5: error: expected ‘;’ before ‘}’ token operators.cpp:83:20: error: expected ‘;’ before ‘)’ token for (symbol=='>') ^ operators.cpp:89:9: error: expected primary-expression before ‘}’ token } ^ operators.cpp:89:9: error: expected ‘)’ before ‘}’ token operators.cpp:89:9: error: expected primary-expression before ‘}’ token operators.cpp:89:9: error: expected ‘;’ before ‘}’ token

我是编程的新手，花了几个小时来修复它，但是我不明白问题是什么。

任何帮助都将不胜感激!

Answer 1

在仔细观察@liup的答案之后添加:

糟糕，我的糟糕，OP可能确实意味着要在此处使用循环!然后，您可以像这样使用while循环:

while (symbol=='<')

和

while (symbol=='>')

旧答案:

这里:

if (symbol=='<')

和这里:

if (symbol=='>')

代替 for (symbol=='<')和 for (symbol=='>')。

该错误源于以下事实:在 for循环中，即使三个子句为空，也必须具有所有三个子句，因此必须使用两个分号 ;。您仅在两个不正确的 for语句的每一个中提供了一个未提供单个分号的位置。

供引用，请参阅 for loop description at cppreference