Convert a QString to an uint8_t

Pantoufle

Hello,

here is my problem :

I have a Qstring that contains "1.2" for example, what i want to do, is having two uint8_t , one with the number 1 inside and the other one with the number 2 inside. (Note that i would want the number, not the Ascii carac).

How i do :

    QPair<uint8_t, uint8_t> _Version = 1.2;
    QStringList versionsNumbers = _Version.split(".");
    _Version.first = static_cast<uint8_t>(versionsNumbers.at(0).toInt());
    _Version.second = static_cast<uint8_t>(versionsNumbers.at(1).toInt());

From what i saw, i cant just make a ".toInt()" without a cast or i would get a warning. And there is no function "toUin8_t", i just find .toUShort.

Is this the right solution?

jsulm

@Pantoufle said in Convert a QString to an uint8_t:

QPair<uint8_t, uint8_t> _Version = 1.2;

I don't get it: you are talking about QString, but here you use a QPair?
What you can do is simply split the string at '.':

QStringList parts = str.split('.');
uint8_t = static_cast<uint8_t>(parts[0].toInt());
// same for the second number

And yes you have to cast.

Pantoufle

Oh sorry i miss copy my code :p

Here the real one :

    QString VersionString = "1.2";
    QPair<uint8_t, uint8_t> _Version;
    QStringList versionsNumbers = VersionString.split(".");
    _Version.first = static_cast<uint8_t>(versionsNumbers.at(0).toInt());
    _Version.second = static_cast<uint8_t>(versionsNumbers.at(1).toInt());

VRonin

Probably not worth it but given it's uint8_t you can use:

const QString _Version = "1.2";
const auto versionsNumbers = _Version.splitRef(".");
std::pair<uint8_t, uint8_t> verNums = std::make_pair<uint8_t, uint8_t>(versionsNumbers.at(0).at(0).unicode()-'0',versionsNumbers.at(1).at(0).unicode()-'0');

Pantoufle

That seems more complicated than my solution to be honest :p

VRonin

@Pantoufle said in Convert a QString to an uint8_t:

That seems more complicated than my solution to be honest :p

Indeed, hence my "Probably not worth it". It's more efficient though

J.Hilk

@Pantoufle said in Convert a QString to an uint8_t:

versionsNumbers

if you're not using versionsNumbers elsewhere in your current scope, I would use splitRef

also list/array size checking before accessing 0 and 1 would be good to have as well.

Pantoufle

@VRonin

Ok good to know.

@J-Hilk

I don't use it elsewhere.
For array size check, i always though that when you use .at(i) instead of [i], there is an automatic check to avoid reading overflow.
Maybe I'm wrong.

VRonin

@Pantoufle said in Convert a QString to an uint8_t:

when you use .at(i) instead of [i], there is an automatic check to avoid reading overflow.

No, value(i) does, at(i) lets it up to you to check

Pantoufle

Ok really good things to know thanks for your help guys