Qt C++: Programming Fundamental Concepts: if-else statement

Program title: if-else statement

C++ Code:

#include <QApplication> 

#include <QDebug>

#include <QMainWindow> //QMainWindow *window

#include <QLabel>

#include <QHBoxLayout> //layout->addWidget(label)

#include <QWidget> //centralWidget->setLayout(layout)

#include <QInputDialog>

#include <QString>

int main(int argc, char *argv[])

{

    QApplication app(argc, argv);

    QMainWindow *window = new QMainWindow();

    QLabel *label = new QLabel("No Result");

    QHBoxLayout *layout = new QHBoxLayout;

    layout->addWidget(label);

    QWidget *centralWidget = new QWidget(window); //centralWidget parent is the window

    centralWidget->setLayout(layout);

    window->setCentralWidget(centralWidget);

    window->setWindowTitle("My Main Window");

    window->resize(400, 400);

    window->show();

    int n = QInputDialog::getInt(window, "Input Dialog",

                                 "Enter a percentage", 25, //25 is the default value

                                 0, 100, 1); //min, max, step

    if(n>=50) {

        qDebug() << "Percentage is greater than or equal to fifty";

        QString s = "Percentage is greater than or equal to fifty";        

        label->setText(s);

    }

    else {

        qDebug() << "Percentage is less than fifty";

        QString s = "Percentage is less than fifty";

        label->setText(s);

    }

    return app.exec();

} 

Program Output: Vertical Toolbar > Run 

Advantages:
-- input dialog: built-in spin box for integer input
-- input dialog: can set default value
-- input dialog: built-in regular expression and input validation
-- input dialog: prevent input error