1  void MainWindow::on_addBtn_clicked()
2  {
3    int x, y, sum;
4    x = ui-> num1->text().toInt();
5    y = ui-> num2->text().toInt();
6    sum = x + y;
7    QString r = "Result is: ";
8    r +=  QString::number(sum);
9    ui->result->setText(r);
10  }