To pass a string between functions

russjohn834

Hi all,

I have a basic c++ question:

I have a class constructor as follows

StageOne::StageOne(QString someLabel, QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::StageOne)
{
    ui->setupUi(this);

    ui->label->setText(someLabel);
    ui->label->setAlignment(Qt::AlignCenter);

}

How do I pass someLabel to other parts of the class, for example, if I need to reuse it in the following function:

void StageOne::on_pushButton_One_clicked()
{
    //----->How do I get "someLabel" from the class constructor here
    
    this->close();
    settingsWindow = new  configsettings (this);
    settingsWindow ->setWindowTitle("Settings window");
    settingsWindow -> show();
}

Thanks in advance

ODБOï

@russjohn834 hi

you can create a member QString variable and assign someLabel s value to it in your constructor

JonB

@russjohn834
As @LeLev has written if you need to reference a parameter all over the place in a class, copy it to a member variable for re-use.

While we are here:

StageOne::StageOne(QString someLabel, QWidget *parent) :

The usual/optimal way of passing QStrings around which you do not intend to alter is via parameter declaration const QString& someLabel. All you do is call QLabel::setText() on this, so see how https://doc.qt.io/qt-5/qlabel.html#text-prop shows setText(const QString &). It's not vital, but if you are going to end up writing loads of code like this you might wish to change your declarations over now.

russjohn834

Thank you @LeLev , @JonB for your feedback