Hello World

[Rabbagast]

Hi. I use the book ''Programming Principles and Practice using C++'' by the creator of C++ Bjarne Stroustrup
The first task was the classic 'Hello world'. In the book there was a code looking like this:

  #include 'std_lib_facilities.h'

int main()
{
	cout << 'Hello World!\n';
	return 0;
}

I tried typing that code, but it didnt work. I then went to youtube and fount another code. That code looked like this;

#include <iostream>

int main() {
    std::cout << "Hello World!" << std::endl;
    std::cin.get();
    return 0;
}

This code worked perfectly fine. I tried to do some modifications on the first code to make it work aswell. i came up with this;

#include <iostream>

int main()
{
	std::cout << "hello world!\n";
	return 0;
}

So basically my question is: Why do this work and not the first? i want learn what everything means so i know next time im writing code. If someone can give a simple and understandable explanation it would be perfect! Thanks.

[iAk3T05o]

Remove the single quotes and try again (newbie too, so don't know if it'll work)

[SorinAlex]

Well basically you needed to download the std_lib_facilities.h header because you didnt had it on your computer.Here is the link : https://www.mediafire.com/?c3t2a8s8pdxau7j
P.S : That header is really just a buch of other headers putted togheter and some extra stuff.

After you downloaded the header just put it in your compiler include folder.

For example : C:\Program Files\CodeBlocks\MinGW\include

or

C:\Program Files\Microsoft Visual Studio 10.0\VC\include

It depends on what complire/ide youve got.

Now you shouldnt receieve the "no such file or directory error".

The code should look like this now:

#include "std_lib_facilities.h"

int main()
{
	cout << "Hello World!\n";
	return 0;
}

As you can see i replaced the ' with " because ' is used for only one character and " is used for more than one character.

[Rabbagast]

@Nathan2222 It does not work.

[Rabbagast]

@SorinAlex Thanks. It worked.

[SorinAlex]

Happy to help :)

[j3Rz8vqX]

Well, for starters:

There is a difference between:
First code:

cout << 'Hello World!\n';

and

Second code:

cout << "Hello World!\n";

Single quotes mean character.
Double quotes mean string.

Character can consist of only one character, ie: 'h' or '5' or '$'

String can consist of multiple characters, ie: "Hello World" or "123456" or "abc456"

cout reference: http://www.cplusplus.com/reference/iostream/cout/
Not sure if the lib is native...

#include 'std_lib_facilities.h' 

if the lib is valid, it should be implemented like this:

#include "std_lib_facilities.h" 

Normally folks using c++ use

#include <iostream> 

The cin.get() isn't necessary but a good way to see your console window open if you're running from an IDE.

[Dy7SLyTq]

well just to do a bit of exanding... a string is one or more characters. ie "a" is a valid string. in c++ they are different data types. in python its all a string.
std_lib_facilities.h is probably something he wrote because its not in the stl. you only use <> in includings when its on the search path. if you wrote it and want to be lazy, then you need to use quotes ie " and cin.get() only works if the buffer is clear

[Pter0dactyl]

I dont know who has written this blog, but Its simple to read.Although its not complete yet.Just give it a look
http://www.programming-gum.blogspot.com