C++ help needed

majinbuu1023 · 05-16-2008, 05:58 AM

I'm trying to learn C++ and when I compile

PHP Code:

  #include <stdio.h>

 
int main()

{

    printf("Lol its line one!\n");

    printf("Line 2\n");

    printf("LINE THREE WTFHAX;\n");

}

in Dev-C++ it just flashes for a second, the book im reading says press alt f5, but this is for C and is pretty old and uses the DOS operating system, anyone know what to do? I made a better script before but closed it because it would work

EDIT: figured it out
add this to the header

HTML Code:

#include <stdlib.h>

then add this
????: NamePros.com http://www.namepros.com/programming/470017-c-help-needed.html

PHP Code:

      system("pause");

to the bottom just above the } tag

CrazyTech · 05-16-2008, 07:03 AM

The same thing happened to me when I was trying to create something similar, so I'll be watching this topic. I couldn't figure out why.

majinbuu1023 · 05-16-2008, 07:12 AM

Awesome

, this is really annoying me, I keep googling it but it isn't showing any results

pixelhero · 05-17-2008, 11:07 AM

Its because the compiler will run the main() method, printing all those lines and then close itself. As a program which leads to the end of the main() method assumes its finished with.

You need to pause it as you did, or ask it to wait for input using the std::cin function.

Alernatively export an exe and run it in command prompt

mholt · 05-19-2008, 07:14 PM

For the record, you're coding C. In C++, your program would resemble:

Code:

#include <iostream>
using namespace std;

int main()
{
    cout << "Lol its line one!" << endl;
    cout << "Line 2" << endl;
    cout << "LINE THREE WTFHAX" << endl;
    system("pause");
    return 0;
}

qbert220 · 05-20-2008, 04:10 AM

Originally Posted by mholt

For the record, you're coding C.

C++ is a superset of C, so the original code is perfectly valid as either C or C++.

Palyriot · 05-20-2008, 10:55 AM

Well, I know in VB and C# you need to have a readline at the end of the program to make it idle and wait for the user to close the window. Just throw a readline command at the end of the program. It should work.

This might not be necessary in C though...

risoknop · 05-20-2008, 11:34 AM

Quote:

#include <stdio.h>

int main()
{
printf("Lol its line one!\n");
printf("Line 2\n");
printf("LINE THREE WTFHAX;\n");
}

The problem is that this algorhitm doesn't wait for any input, it just resolves and shuts down. You need to include getchar() and return 0... Here:

Quote:

#include <stdio.h>

int main()
{
printf("Lol its line one!\n");
printf("Line 2\n");
printf("LINE THREE WTFHAX;\n");
getchar();
getchar();
return 0;
}

What does getchar() do? It stops the program and waits until you press enter - then the program continues (it can also be used to recognize what key did user press...).

return 0 ends the program.

By the way, that is pure C code - you don't use any C++ functions or libraries there

In C++ it would be like this:

Quote:

#include <iostream>
using namespace std;

int main()
{
cout >> "Lol its line one!\n";
cout >> "Line 2\n";
cout >> "LINE THREE WTFHAX;\n";
getchar();
getchar();
????: NamePros.com http://www.namepros.com/showthread.php?t=470017
return 0;
}

mholt · 05-20-2008, 06:38 PM

Originally Posted by risoknop

The problem is that this algorhitm doesn't wait for any input, it just resolves and shuts down. You need to include getchar() and return 0... Here:

What does getchar() do? It stops the program and waits until you press enter - then the program continues (it can also be used to recognize what key did user press...).

return 0 ends the program.

By the way, that is pure C code - you don't use any C++ functions or libraries there

In C++ it would be like this:

Did you even read the thread - no - just his original post even? You just made yourself look rather unintelligent...

Originally Posted by qbert220

C++ is a superset of C, so the original code is perfectly valid as either C or C++.

True, however while the code is valid, I don't think that you can say the above code is C++ just by looking at that. I think in order for it to be C++ you need to use at least one C++ concept/aspect/feature.
????: NamePros.com http://www.namepros.com/showthread.php?t=470017

Header files with .h extension generally are not in and of themselves C++, as they are plain ol' C libraries.

Oh well. Doesn't matter.

RageD · 05-20-2008, 07:45 PM

Are you trying to create a command prompt or WinAPI? I can help if you let me know. I wouldn't recommend using 'printf' for command prompt in C++

programming with 'cout >>' - a lot better for your purposes.

-RageD

risoknop · 05-21-2008, 11:39 AM

Quote:

Did you even read the thread - no - just his original post even? You just made yourself look rather unintelligent...

Maybe I'm just too tired but I really don't see how I've made myself look dumb. Care to explain?

If I did then I apologize.

mholt · 05-21-2008, 12:30 PM

Well, he stated his resolution at the bottom of his OP, then you just repeated what was already said in the thread. I've made similar mistakes too... we all do.

risoknop · 05-21-2008, 03:27 PM

Yeah I messed up. Sorry, my bad.

mholt · 05-21-2008, 10:03 PM

Lol, it's fine... I see you're sorta new here, so I guess it's just a heads up to read the thread. Anyway, welcome to NamePros. It's great that you are contributing, and we all love to see it!

05-16-2008, 05:58 AM	THREAD STARTER #1 (permalink)
majinbuu1023 Senior Member Join Date: Jan 2005 Location: New Zealand Posts: 3,746	C++ help needed I'm trying to learn C++ and when I compile PHP Code: `#include <stdio.h> int main() { printf("Lol its line one!\n"); printf("Line 2\n"); printf("LINE THREE WTFHAX;\n"); }` in Dev-C++ it just flashes for a second, the book im reading says press alt f5, but this is for C and is pretty old and uses the DOS operating system, anyone know what to do? I made a better script before but closed it because it would work EDIT: figured it out add this to the header HTML Code: #include <stdlib.h> then add this ????: NamePros.com http://www.namepros.com/programming/470017-c-help-needed.html PHP Code: `system("pause");` to the bottom just above the } tag __________________ WowHumor.net - Funny World of Warcraft Pictures Last edited by majinbuu1023; 05-16-2008 at 09:56 PM.

05-16-2008, 07:12 AM	THREAD STARTER #3 (permalink)
majinbuu1023 Senior Member Join Date: Jan 2005 Location: New Zealand Posts: 3,746	Awesome , this is really annoying me, I keep googling it but it isn't showing any results __________________ WowHumor.net - Funny World of Warcraft Pictures

05-17-2008, 11:07 AM	#4 (permalink)
pixelhero NamePros Regular Join Date: May 2008 Location: England Posts: 771	Its because the compiler will run the main() method, printing all those lines and then close itself. As a program which leads to the end of the main() method assumes its finished with. You need to pause it as you did, or ask it to wait for input using the std::cin function. Alernatively export an exe and run it in command prompt __________________ pixelhero Web Development Studios UK

05-19-2008, 07:14 PM	#5 (permalink)
mholt DNOA Member Join Date: May 2004 Posts: 5,040	For the record, you're coding C. In C++, your program would resemble: Code: #include <iostream> using namespace std; int main() { cout << "Lol its line one!" << endl; cout << "Line 2" << endl; cout << "LINE THREE WTFHAX" << endl; system("pause"); return 0; } Last edited by mholt; 05-20-2008 at 06:43 PM.

05-20-2008, 07:45 PM	#10 (permalink)
RageD Senior Member Join Date: Apr 2005 Location: Joliet, Illinois Posts: 1,177	Are you trying to create a command prompt or WinAPI? I can help if you let me know. I wouldn't recommend using 'printf' for command prompt in C++ programming with 'cout >>' - a lot better for your purposes. -RageD __________________ Microsonic Development New Programming Video Tutorials

05-16-2008, 07:03 AM	#2 (permalink)
CrazyTech NamePros Expert Join Date: Oct 2004 Location: South Carolina Posts: 5,043	The same thing happened to me when I was trying to create something similar, so I'll be watching this topic. I couldn't figure out why.

05-20-2008, 10:55 AM	#7 (permalink)
Palyriot NamePros Regular Join Date: Jul 2004 Location: Seattle, Wa Posts: 596	Well, I know in VB and C# you need to have a readline at the end of the program to make it idle and wait for the user to close the window. Just throw a readline command at the end of the program. It should work. This might not be necessary in C though...

05-21-2008, 12:30 PM	#12 (permalink)
mholt DNOA Member Join Date: May 2004 Posts: 5,040	Well, he stated his resolution at the bottom of his OP, then you just repeated what was already said in the thread. I've made similar mistakes too... we all do.

05-21-2008, 03:27 PM	#13 (permalink)
risoknop NamePros Member Join Date: Apr 2008 Posts: 82	Yeah I messed up. Sorry, my bad. __________________ Richard Knop \| Freelance Web developer and Web designer Zend Framework blog

05-21-2008, 10:03 PM	#14 (permalink)
mholt DNOA Member Join Date: May 2004 Posts: 5,040	Lol, it's fine... I see you're sorta new here, so I guess it's just a heads up to read the thread. Anyway, welcome to NamePros. It's great that you are contributing, and we all love to see it!

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