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Newbie Question (Hello World)

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Join Date: May 2005

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Reputation: ehsen is an unknown quantity at this point

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ehsen

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Newbie Poster

Newbie Question (Hello World)

Sep 3rd, 2007

I started to learn C++ few days ago. When I Run a program it show a console window for a moment then return to IDE. I even couldn't see the output.
for example followig Hello World Program

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
// a small C++ program
#include <iostream>
using namespace std;
int main()
{
    cout << "Hello, world!" << endl;
 
}
// a small C++ program
#include <iostream>
using namespace std;
int main()
{
    cout << "Hello, world!" << endl;
    
}

what should I add in this code (infact every code) to stop this problem. I tried to fix it myself by adding cin.ignore(); at the end of the program. But this doesn't workout where program requires the input from user.

Last edited by ehsen; Sep 3rd, 2007 at 2:56 am.

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Join Date: Nov 2006

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Reputation: n.aggel is an unknown quantity at this point

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n.aggel

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Posting Whiz in Training

Re: Newbie Question (Hello World)

Sep 3rd, 2007

i am not in front of windows, so i can't test the advise::

try inserting system("pause"); and in the beginning <include> <cstdlib>

-i am not sure about which library to include...i am sure about the system command

another way would be to declare a dummy variable and read it at the end of the programm....

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Join Date: Mar 2007

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Reputation: ft3ssgeek is an unknown quantity at this point

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ft3ssgeek

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Junior Poster

Re: Newbie Question (Hello World)

Sep 3rd, 2007

I would not recommend using

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system("pause");
system("pause");

as it is not portable between various operating systems...try something like

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cin.get();
cin.get();

at the end instead...

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Join Date: Jun 2007

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Reputation: Hamrick will become famous soon enough

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Hamrick

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Posting Whiz

Re: Newbie Question (Hello World)

Sep 3rd, 2007

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I tried to fix it myself by adding cin.ignore(); at the end of the program. But this doesn't workout where program requires the input from user.

It doesn't work because there's still something in the stream and ignore gets it right away. You should clear the stream first then do ignore or get.

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#include <iostream>
 
using namespace std;
 
void BlockPause() {
  // Set the state so cin can read.
  cin.clear();
 
  // Clear everything in the stream
  cin.sync();
 
  // Do the pause
  cin.ignore();
}
 
int main() {
  // All of your other code goes here
 
  // Pause at the end with BlockPause
  cout<<"Press enter to continue...";
  BlockPause();
 
  return 0;
}
#include <iostream>

using namespace std;

void BlockPause() {
  // Set the state so cin can read.
  cin.clear();

  // Clear everything in the stream
  cin.sync();

  // Do the pause
  cin.ignore();
}

int main() {
  // All of your other code goes here

  // Pause at the end with BlockPause
  cout<<"Press enter to continue...";
  BlockPause();

  return 0;
}

cin.clear() makes the stream state good. If it's not good, cin won't read anything ever. cin.sync() clears all of the characters left in the stream so that the next cin.ignore() or cin.get() stops the program waiting for input.

The truth does not change according to our ability to stomach it.

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Join Date: Aug 2007

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Reputation: fzafarani is an unknown quantity at this point

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fzafarani

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Light Poster

Re: Newbie Question (Hello World)

Sep 3rd, 2007

You should use
getch();
at the end!

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

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

or press alt+F5 at the end of program.

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Join Date: Apr 2004

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Reputation: Dave Sinkula has a brilliant future

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Dave Sinkula Dave Sinkula is offline

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long time no c

Re: Newbie Question (Hello World)

Sep 3rd, 2007

•

Originally Posted by fzafarani

You should use
getch();
at the end!

No you really shouldn't. It's non-portable.

Better would be to learn how to execute a command-line program from the command line.

And please use [code][/code] tags.

Last edited by Dave Sinkula; Sep 3rd, 2007 at 4:03 pm.

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Join Date: Sep 2007

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sd.lamba

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Newbie Poster

Re: Newbie Question (Hello World)

Sep 4th, 2007

add
#include<iostream.h>
#include<conio.h>
int main()
{
cout<<"hello world";
getch(); //is used to hold the o/p screen
return 0; //will return the value to O.S.
}