qstring.mid() questions

[martial_arts_drummer]

Ok, I can't figure out why this is not working:

QString temp_vol_id = temp_string;
int first_dot = temp_string.indexOf(".");
int last_dot = temp_string.lastIndexOf(".");
QString temp_name = temp_string.mid((first_dot+1),((last_dot-first_dot)-1))

QString temp_vol_id = temp_string;
int first_dot = temp_string.indexOf(".");
int last_dot = temp_string.lastIndexOf(".");
QString temp_name = temp_string.mid((first_dot+1),((last_dot-first_dot)-1))

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where temp_vol_id = a valid 82 char qstring
first_dot = 47
last_dot = 61

the debugger states temp_name is <invalid>
I attempted changing qstring.mid second parameter to -1 (it should extract from
first_dot to end of string, but that also returns <invalid>

I am using similar statements in other sections of the code successfully.
Can anyone see anything incorrect in this snippet of code?

thanks

John

---

Added after 5 minutes:

I should have included the complete function for clarity:

QString Widget::get_Vol_ID(QString temp_string)
{
    QString temp_vol_id = temp_string;
    int first_dot = temp_vol_id.indexOf(".");
    int last_dot = temp_vol_id.lastIndexOf(".");
    QString temp_name1 = temp_vol_id.mid((first_dot+1),((last_dot-first_dot)-1));
  //  QString temp_name = temp_vol_id.mid(first_dot,-1);
 //   QString temp_name = temp_vol_id.mid((first_dot+1),((last_dot-first_dot)-1));
    QString temp_noise = "";
    return(temp_name1);
 
}

QString Widget::get_Vol_ID(QString temp_string)
{
    QString temp_vol_id = temp_string;
    int first_dot = temp_vol_id.indexOf(".");
    int last_dot = temp_vol_id.lastIndexOf(".");
    QString temp_name1 = temp_vol_id.mid((first_dot+1),((last_dot-first_dot)-1));
  //  QString temp_name = temp_vol_id.mid(first_dot,-1);
 //   QString temp_name = temp_vol_id.mid((first_dot+1),((last_dot-first_dot)-1));
    QString temp_noise = "";
    return(temp_name1);

}

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you can see the commented out lines that were attempted (without success)

thanks

John

[Lykurg]

Hm, there is no error in the code. It works well on my side. Please add

qWarning() << Q_FUNC_INFO << temp_vol_id << first_dot << last_dot;

qWarning() << Q_FUNC_INFO << temp_vol_id << first_dot << last_dot;

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before the return of your function and post the output in the cases where it do not work like expected.