QString Resets after appending 10 characters-CodePudding

I just started QT Language. A strange error occurred when I tried appending a character 10 times to it. It resets and starts over. Does anyone know a solution?

QString tempLabel = "0";

void MainWindow::AppendToLabel(int s){
    //QString LabelText = ui->displayText->text();

    //testCase
    QString LabelText = tempLabel;

    // Updates the label acording to the button
    if(tempLabel.toInt() == 0)
    {
        // If the Number 0 present in the label - Rplace it
        LabelText = QString::number(s);
    }
    else
    {
        // If not not - Append it to the label
        LabelText.append(QString::number(s));
    }

    double apendedNumber = LabelText.toDouble();
    qDebug() << LabelText;
    tempLabel = LabelText;
    //ui->displayText->setText(LabelText);
}

When I append the 11th character, it replaces the whole string instead of appending it to the existing one.

CodePudding user response：

A 32-bit integer value can have a maximum value of 2^31 - 1, or 2147483647, which happens to be 10 digits long. So an 11 digit number would fail when calling toInt().

QString s = "12345678901"
qDebug() << s.toInt();  // prints '0'

CodePudding user response：

The upper size limit for any QString value is 4GB. You should find a bug in your code...

QString::toInt() and QString::toDouble() can return zero if it can not convert, set a bool parameter to check is converted success like these

bool flag;
int v = tempLabel.toInt(&flag);