Programming Forums > Application Development > C++

joeiscool · Mar 7th, 2006, 5:20 AM

Hi I am using bloodshed DEV-C++ Compiler and I write the C++ code and compile it it compiles then I debug it it says there are no bugs but for some reason every time a run the program,the program opens and then closes right away and I cant see what it's suppose to print. Which is Hello World Im a C++ program. Any help would be appreciated.

d_heyzie · Mar 7th, 2006, 5:34 AM

I just include a file called "conio.h" and before I type "return 0;" i put the "getch()" function so it look similar to this:

(Toggle Plain Text)

#include <iostream>
#include <conio.h>

using namespace std;

int main()
{
    cout <<"Hello World";
    
    getch();
    return 0;
}

probably some other way to do it though

joeiscool · Mar 7th, 2006, 5:42 AM

It worked I appreciate you helping me out.

nnxion · Mar 7th, 2006, 6:30 AM

Again this is a question that is asked a lot of times already. conio.h is not portable, instead one might want to use cin.get() instead. It requires a return character (read: press the enter key), instead of just any key though.

d_heyzie · Mar 8th, 2006, 1:40 AM

sorry if it seems like im taking over this post.. but ive seen cin.get() in alot of examples but for some reason it never works for me when i need to input a number and get a result, i input the number and the result flashes up and the program closes. Can someone tell me why?

grumpy · Mar 8th, 2006, 2:34 AM

Because the result is displayed and the program immediately exits (eg drops off the end of main()). When the program exits, the associated console that the program's output is being displayed to is terminated by the OS, as it is no longer needed. This happens pretty quickly, so you don't get to see the program output before the console is destroyed.

You either need to stop the program from exiting (eg place a cin.get() just before main() completes and AFTER the last line of output that you want to see) or run the program from a command prompt (which makes the console have a lifetime unconnected from the execution of the program you're running).

d_heyzie · Mar 8th, 2006, 3:38 AM

so do i put a cin.get() before i make it return a value? if so thats exactly where i put it but it still just flashes up and terminates.

grumpy · Mar 8th, 2006, 6:44 AM

There are a number of variants of the get() method (each taking a different set of arguments). Some return immediately if there is no input pending. Others wait for input. You obviously need to use one of the latter ......

DaWei · Mar 8th, 2006, 7:49 AM

Another problem is if the previous input has not all been used. Then the final cin.get () will see the unused input, grab it, zoop right on by, and exit. Put cin.sync () prior to the final cin.get ().

(Toggle Plain Text)

   ....
   .... program code
   ....
   cin.sync ();
   cin.get ();
   return 0;
}

HaCkeR · Mar 8th, 2006, 2:43 PM

And for some reason if your like me and even Dawei's method doesnt work ad
cin.clear();

before cin.get();

Mar 7th, 2006, 5:20 AM	#1
joeiscool Newbie Join Date: Mar 2006 Posts: 6 Rep Power: 0	C++ program self termination Hi I am using bloodshed DEV-C++ Compiler and I write the C++ code and compile it it compiles then I debug it it says there are no bugs but for some reason every time a run the program,the program opens and then closes right away and I cant see what it's suppose to print. Which is Hello World Im a C++ program. Any help would be appreciated.

Mar 7th, 2006, 5:34 AM	#2
d_heyzie Newbie Join Date: Jan 2006 Posts: 22 Rep Power: 0	I just include a file called "conio.h" and before I type "return 0;" i put the "getch()" function so it look similar to this: (Toggle Plain Text) #include <iostream> #include <conio.h> using namespace std; int main() { cout <<"Hello World"; getch(); return 0; } #include <iostream> #include <conio.h> using namespace std; int main() { cout <<"Hello World"; getch(); return 0; } probably some other way to do it though

Mar 7th, 2006, 5:42 AM	#3
joeiscool Newbie Join Date: Mar 2006 Posts: 6 Rep Power: 0	Thank You It worked I appreciate you helping me out.

Mar 7th, 2006, 6:30 AM	#4
nnxion Programming Guru Join Date: Jun 2005 Location: elemental plane Posts: 1,429 Rep Power: 5	Again this is a question that is asked a lot of times already. conio.h is not portable, instead one might want to use cin.get() instead. It requires a return character (read: press the enter key), instead of just any key though. __________________ "Employ your time in improving yourself by other men's writings, so that you shall gain easily what others have labored hard for." -- Socrates

Mar 8th, 2006, 2:34 AM	#6
grumpy Programming Guru Join Date: Jun 2005 Location: Adelaide, South Australia Posts: 1,261 Rep Power: 5	Because the result is displayed and the program immediately exits (eg drops off the end of main()). When the program exits, the associated console that the program's output is being displayed to is terminated by the OS, as it is no longer needed. This happens pretty quickly, so you don't get to see the program output before the console is destroyed. You either need to stop the program from exiting (eg place a cin.get() just before main() completes and AFTER the last line of output that you want to see) or run the program from a command prompt (which makes the console have a lifetime unconnected from the execution of the program you're running). Last edited by grumpy; Mar 8th, 2006 at 3:03 AM.

Mar 8th, 2006, 1:40 AM	#5
d_heyzie Newbie Join Date: Jan 2006 Posts: 22 Rep Power: 0	sorry if it seems like im taking over this post.. but ive seen cin.get() in alot of examples but for some reason it never works for me when i need to input a number and get a result, i input the number and the result flashes up and the program closes. Can someone tell me why?

Mar 8th, 2006, 3:38 AM	#7
d_heyzie Newbie Join Date: Jan 2006 Posts: 22 Rep Power: 0	so do i put a cin.get() before i make it return a value? if so thats exactly where i put it but it still just flashes up and terminates.

Mar 8th, 2006, 6:44 AM	#8
grumpy Programming Guru Join Date: Jun 2005 Location: Adelaide, South Australia Posts: 1,261 Rep Power: 5	There are a number of variants of the get() method (each taking a different set of arguments). Some return immediately if there is no input pending. Others wait for input. You obviously need to use one of the latter ......

Mar 8th, 2006, 7:49 AM	#9
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	Another problem is if the previous input has not all been used. Then the final cin.get () will see the unused input, grab it, zoop right on by, and exit. Put cin.sync () prior to the final cin.get (). (Toggle Plain Text) .... .... program code .... cin.sync (); cin.get (); return 0; } .... .... program code .... cin.sync (); cin.get (); return 0; } __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Mar 8th, 2006, 2:43 PM	#10
HaCkeR Hobbyist Programmer Join Date: Nov 2005 Location: UK Posts: 131 Rep Power: 0	And for some reason if your like me and even Dawei's method doesnt work ad cin.clear(); before cin.get();

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Programming Forums > Application Development > C++

C++ program self termination