Question

我在Xcode中遇到此代码时出现问题：

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main()
{
    ofstream out;
    char c;
   out.open("call_data.txt");
   if (out.fail())
       cout << "failed." << endl; exit(1);
   cout << "Print something to a file :" << exit(1);//I get the error here
   cin >> c;
   out << c;
   out.close();
   return 0;
}

有人能告诉我为什么会收到这个错误吗？我无法弄清楚。我可能错误地打开输出流吗？我觉得它之前就像这样。

Answer 1

使用合理的格式化代码如下所示：

ofstream out;
char c;
out.open("call_data.txt");
if (out.fail())
   cout << "failed." << endl;
exit(1);
cout << "Print something to a file :" << endl; //exit(1) shouldn't be here either
cin >> c;
out << c;
out.close();

始终会发生对exit的调用，以后无法访问任何内容。使用{}表示多语句if：

if (out.fail()) {
    cout << "failed." << endl;
    exit(1);
}

Answer 2

您的错误可能是因为您忘记在if语句中使用括号。这是它应该是什么样子：

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main()
{
    ofstream out;
    char c;
   out.open("call_data.txt");
   if (out.fail())
   {
       cout << "failed." << endl;
       exit(1);
   }
   cout << "Print something to a file :" << exit(1);//I get the error here
   cin >> c;
   out << c;
   out.close();
   return 0;
}

错误，“代码永远不会执行”，带输出流

2 个答案: