Program Terminating too quickly.

[DontdroptheSOAD]

Alright at the moment I am using a cin>> with a variable in order to keep the program from exiting before I can see the results. I am wondering if there is a better way to keep the window open.

[arul]

Don't know if it's the best way ( I'm learning C++ too ) but I would rather use cin.get() instead of declaring a slave variable.

cin.get();

[DontdroptheSOAD]

that doesn't seem to stop it from closing. Maybe I am using it wrong @_@

[DontdroptheSOAD]

I found out what it is, the compiler I use runs it in a shell that closes when it is through. When i launch it from a command prompt it stops.

grrr. It still isn't what I want. When I launch the exe it opens it and closes it as soon as the results are displayed.

This is with cin.get();

[Sep102]

One of the best C++-standard way to do this is to use the istream::ignore() method with cin, ala

#include <iostream>
#include <limits>

...

std::cin.ignore(std::numeric_limits<std::streamsize>::max(), 'z');

This will extract and discard as many characters as can fit into a stream up until the character 'z' is found, then that is extracted, discarded, and the statement ends. The first argument is the number of characters to remove and the second is an optional delimiter to stop ignoring at.

[DontdroptheSOAD]

Originally Posted by Sep102

One of the best C++-standard way to do this is to use the istream::ignore() method with cin, ala

#include <iostream>
#include <limits>

...

std::cin.ignore(std::numeric_limits<std::streamsize>::max(), 'z');

This will ignore as many characters as can fit into a stream up until the character 'z' is ignored. The first argument is the number of characters to ignore and the second is an optional delimiter to stop ignoring at.

so if z is pressed it will terminate?

[Sep102]

Yes, if 'z' is entered to cin it will end and (almost) only when 'z' is entered.

[DontdroptheSOAD]

Excellent, once again you have been very helpful

[xir]

Something I don't really like with the new VC++ .NET. The old VC6 used keep the console open. What I do is add a breakpoint just before the main() function ends and then run it in debug.

If someone has a solution to make it work like the old VC6 I'd be interested in knowing too

[Sep102]

I don't exactly know the answer to that, however on both machines that I've installed the entirety of VS.NET 2003 on (one heavily configured and the other fully-default installed and unconfigured) both prompt me before quitting the application, thereby alleviating the need for me to do any of this, as do all of the other machines running it at my school.

[xir]

If you use the red exclamation mark to run the program or Ctrl+F5 it will bring up the prompt asking to close once the program has finished. It just doesn't work in debug, but I can live with that ;/

[Sep102]

Ahh, well you see, you're not supposed to be running in debug mode all of the time testing, just when something actually does "go to shit" (so to speak) and you need debug mode to fix it.

[ZaSz-RH]

You can also use

system("PAUSE");

It's like a pause in DOS, any entry will close the program.

[Sep102]

Originally Posted by ZaSz-RH

You can also use

system("PAUSE");

It's like a pause in DOS, any entry will close the program.

However the one problem with that is the fact that it is a nonportable way of pausing, moving the program to another platform than Windows may very well cause it to "break" (so to speak, as not pausing may or may not be seen as the program breaking).

The way I presented is one of the few completely portable (as in, as long as the compiler supports the ISO C++ standard well enough) ways enacting a pause in the program.

[p4tRi0t3]

use system pause :

system( "PAUSE" );

It will show a message and wait any key press

[DontdroptheSOAD]

I do like the pause method, it is nice however i would like programs I write to be available in all supporting os's also I was wondering if I can use the method you mentioned Sep to work with the enter key. Because pressing a key and then hitting enter seems redundent. Like when a program says press anykey to exit it is just one thing to do rather than the "is that your final answer" approach by typing the key and then pressing enter.

[Sep102]

You can, to a point. When the enter key is pressed in a console, any characters are first read by an input device (or extracted and discarded with ignore) then a newline character is generated at the end ('\n') so ignoring up until a newline character will do what you want.

However, one caveat to this is if any other newline characters are still in the input buffer (via an earlier input or something of the sort) then the one ignore() will find that newline and end the statement without waiting like you wanted. This is not normal program flow however, as long as the user of the program enters only what they are supposed to, one could very well write a program with input where this would not happen.

Thus for safety in a program with user-supplied inputs, use two ignore() statements at the end with a newline delimiter, with no user-supplied input, one ignore().

[Shadow-Sigma]

in MSVC 2005:

1. CTRL+F5 to compile in debug, returns a "Press any key to continue..." prompt.

2. system("PAUSE"); returns a "Press any key to continue..." prompt

3. cin.get(); waits for any key input

4. Make a batch file and add a system("PAUSE");, returns a "Press any key to continue..." prompt

[Killamus]

#include "conio.h"
char c = '\n';
while ( c = getch() && c != 'yourchar' )
{
}

Standard C lib, I'd think it'd be supported on any OS, though I don't honestly know. Basically, it'll keep asking for a new character until it gets the one it likes.