Thread: Read File in Switch

The following piece of code (which will read a number from input.txt, provided of course that you enter 0) will compile and run fine:

Code:

#include <iostream.h>
#include <fstream.h>
#include <stdlib.h>

int main()
{

int n;
cin >> n;

switch (n)
{
case 0:
     char buffer[256];
     ifstream inputfile ("input.txt");
     if (! inputfile.is_open())
     {
          cout << "Error opening file";
     }
     while(! inputfile.eof() )
     {
          inputfile.getline (buffer,100);
          n = atol(buffer);
          cout << n;
     }
     break;
}
}

However, if I add another case into the switch, it will not compile:

Code:

switch (n)
{
case 0:
     char buffer[256];
     ifstream inputfile ("input.txt");
     if (! inputfile.is_open())
     {
          cout << "Error opening file";
     }
     while(! inputfile.eof() )
     {
          inputfile.getline (buffer,100);
          n = atol(buffer);
          cout << n;
     }
     break;
case 1:
     break;
}

Why does adding that other case make it not work?

P.S. I know the code is very strange... it is part of a program I am writing that does make sense, but I have identified this as the problem.

Thanks!

When you declare variables inside a switch case, you use brackets ( { } ) I believe. Thus making your code more like:

Code:

	switch (n)
	{
		case 0:
		{
			somevar var;
			... code here....
			break;
		}
		case 1:
			....more stuff
			break;
	}

Edit: You know just for kicks I should mention you should knock the .h from your header file declarations. It's some C++ ANSI standard. http://www.google.com/search?q=c%2B%2B+header+files

> Why does adding that other case make it not work?
Well stating OS, Compiler and error messages would be a start.

> #include <iostream.h>
If your compiler doesn't support this, then you need to upgrade.
#include <iostream>
using namespace std;

> while(! inputfile.eof() )
Read the FAQ as to why eof() in control loops doesn't do what you think it does.