Qt4/Qt-Creator Hello World Console Mode

--D. Thiebaut 01:49, 2 June 2010 (UTC)

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This tutorial illustrates how to use Qt Creator to create a simple console-mode "hello world" application on a Mac running OS X.

Setup

We assume that you have installed Qt Creator and Qt 4 on your Mac (or Windows/Linux platform).

Steps

• Start Qt Creator
• File/New File or Project
• Pick Qt4 Console Application

• Pick a name for the project directory, say, helloWorld_console
• Pick a full path for the directory, say, /Users/yourName/Qt4/
• Accept the default module list
• click Done
• You have a new project with a main.cpp file and a helloWorld_console.pro file.

main.cpp

• Simply edit the code as follows:

#include <QtCore/QCoreApplication>
#include <QDebug>

int main(int argc, char *argv[])
{
    //QCoreApplication a(argc, argv);
    qDebug() << "hello world!" << endl;
    //return a.exec();
}

Running the program

Running from inside Qt Creator

• Simply type Apple-R to run the program.
• Verify that you get an output in the Application Output window.

hello world!

Running from the Terminal

• Open a terminal window, and cd to the directory containing the project, and run the newly created file:

  $: cd /Users/yourName/Qt4/helloWorld_console
  $: ls 
    Makefile		helloWorld_console.pro	main.o
    helloWorld_console*	main.cpp

  $:  ./helloWorld_console 
  hello world!

Variants

Here are several other variants of the main program.

Variant #1

#include <iostream>

int main()
{
  std::cout << "\nHello World!\n";
}

Variant #2

#include <QTextStream>

int main()
{
   QTextStream out(stdout);
   out << "\nHello World!\n";
}