[Solved] Modulo operator %

McLion

Hi

Following sample from standard C:
where for instance a = 1234 (value) and b = 10000000 (scaling factor)
printf("value: %d.%6.6d\n", ( a / b ), ( a % b ));
would return: value: 0.001234

I now tried to do something similar in Qt:

ui->Label->setText(tr("value: %1.%2")
.arg(data.section(' ', 7, 7).toUInt(&ok, 10) / data.section(' ', 8, 8).toUInt(&ok, 10))
.arg(data.section(' ', 7, 7).toUInt(&ok, 10) % data.section(' ', 8, 8).toUInt(&ok, 10), 7));

which leads me to
value: 0. 1234
and I can not manage to have it filled with '0' instead of ' '.

What am I doing wrong?
Thanks

koahnig

@McLion
One way I can think off is using the QTextStream::setPadChar. You have to write to a string there.
Personally I would prefer using std::ostringstream, but basically do the same.

Chris Kawa

I might be missing something but why not just do this?

QString::number((double)a/b, 'f', 6);

Btw. 1234/10000000 is 0.0001234 not 0.001234 so your padding in the first example is flawed.

McLion

Thank you guys.
I got it solved. I extended the .arg() with the padding which in the first place did not work because I forgot the QChar casting. Here's how it works:

ui->label->setText(tr("BER: %1.%2")
.arg(data.section(' ', 7, 7).toUInt(&ok, 10) / data.section(' ', 8, 8).toUInt(&ok, 10))
.arg(data.section(' ', 7, 7).toUInt(&ok, 10) % data.section(' ', 8, 8).toUInt(&ok, 10), 6, 10, QChar('0')));

@Chris-Kawa:
You're right. 6 is correct ... typo.

btw: I still could not figure how to mark as code in the new forum ..

Chris Kawa

@McLion To post code surround it with backticks i.e. ```your code here``` for a code block or `your code` for inline code.

McLion

Thanks.
I tried with the forward and the straight tick but missed to try with the backward.