check if value is int or numeric

[Swankee]

Last night I has asked for a validator to for checking if a number was an int and I got a good hand. One of my co-workers told me they're going to need a double. The code will throw an error for white space and for special characters so I'm not sure what the approach is. Thanks for the clarificatioin

double GateOverlapFactor::on_okButton_clicked()
{
    QString isNumber = m_ui->lineEdit->text();
    QString trueNumber = "";    
    QString str = m_ui->lineEdit->text();
    double returnDouble;
 
    foreach(QChar c, str)
    {
        if(c.isNumber()) //check numeric input
        {
            trueNumber = m_ui->lineEdit->text();
 
            close();
        }
        if(isspace(true))  // Check for whitespace
        {
            m_ui->messageLbl->setText(m_ui->lineEdit->text() + "Enter a Numeric Value");            
        }
        else // not numeric?, throw error
        {
        m_ui->messageLbl->setText(m_ui->lineEdit->text() + ":  Is Invalid.  Enter a Numeric Value");
 
        }
    }
 
    returnDouble = trueNumber.toDouble();
 
    return returnDouble;
}

double GateOverlapFactor::on_okButton_clicked()
{
    QString isNumber = m_ui->lineEdit->text();
    QString trueNumber = "";    
    QString str = m_ui->lineEdit->text();
    double returnDouble;

    foreach(QChar c, str)
    {
        if(c.isNumber()) //check numeric input
        {
            trueNumber = m_ui->lineEdit->text();

            close();
        }
        if(isspace(true))  // Check for whitespace
        {
            m_ui->messageLbl->setText(m_ui->lineEdit->text() + "Enter a Numeric Value");            
        }
        else // not numeric?, throw error
        {
        m_ui->messageLbl->setText(m_ui->lineEdit->text() + ":  Is Invalid.  Enter a Numeric Value");

        }
    }

    returnDouble = trueNumber.toDouble();

    return returnDouble;
}

To copy to clipboard, switch view to plain text mode 

[RSX]

If you want to enter only double values in line edit then all you need is:

QDoubleValidator* validator = new QDoubleValidator(this);
m_ui->lineEdit->setValidator(validator);

QDoubleValidator* validator = new QDoubleValidator(this);
m_ui->lineEdit->setValidator(validator);

To copy to clipboard, switch view to plain text mode 

[Swankee]

If you want to enter only double values in line edit then all you need is:

QDoubleValidator* validator = new QDoubleValidator(this);
m_ui->lineEdit->setValidator(validator);

QDoubleValidator* validator = new QDoubleValidator(this);
m_ui->lineEdit->setValidator(validator);

To copy to clipboard, switch view to plain text mode 

thank you so much, was on vacation last week