Have dynamic combobox based on changes in another combobox

My application currently has 2 comboboxes on the main form. The first combobox has 14 items, but 5 categories. I would like to list the categories in an additional combobox that I would place on the form above the 14 item combobox. Then populate dynamically the original 14 item combobox (doing a clear()) first) with items based on the category combox selection. I think I've found how to clear and add items, but I don't know how to connect the signal. Any help would be greatly appreciated. Thanks.

I got it working using a connect slot and a better alternative method too. No need to reply.

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Added after 24 minutes:

The connect slot solution is:

Code:

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connect(ui->comboBox, static_cast<void (QComboBox::*)(const QString &)>(&QComboBox::currentIndexChanged), this, &MainWindow::setGames);

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An alternative and easier solution is:

Code:

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void MainWindow::on_comboBox_currentTextChanged(const QString &arg1)
{
    if (arg1 == "first") {
        ui->comboBox_2->clear();
        ui->comboBox_2->addItem("1");
    }
    else if (arg1 == "second") {
        ui->comboBox_2->clear();
        ui->comboBox_2->addItem("2");
    }
    else if (arg1 == "third") {
        ui->comboBox_2->clear();
        ui->comboBox_2->addItem("3");
    }
 
}

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