Convert QString in format of Decimal String to appropiate Hex String format.

Ayush Gupta

I have below scenario

I have QString for bytesize = 1 , byteSize = 2 byteSize =3
Suppose
QString test("65") ; [for bytesize = 1 i.e char]
I need to convert it to hex string and hex string should contain value (41)

How can i do that in QT?

Gojir4

@Ayush-Gupta Hi,

QString test("65") ;
bool ok = false;
quint32  iTest = test.toUInt(&ok, 10);
if(ok) {
    QString hex = QString("%1").arg(iTest, 2, 16);
   //hex contains now "41"
} else {
   //String to int conversion error
}

Shorter version (without testing conversion error)

QString test("65");
QString hex = QString("%1").arg(test.toUInt(), 16);

raven-worx

@Ayush-Gupta
~~QString("65").toLatin1().toHex();~~

Gojir4

@raven-worx said in Convert QString in format of Decimal String to appropiate Hex String format.:

QString("65").toLatin1().toHex();

This gives "3635" and not "41"

raven-worx

@Gojir4 said in Convert QString in format of Decimal String to appropiate Hex String format.:

This gives "3635" and not "41"

right, my fault

Ayush Gupta

No this does not works for me
consider scenario
QString test("-23") ; //and its of char size then -23 should be represent

int32 iTest = test.toUInt(&ok, 10);
if(ok) {
QString hex = QString("%1").arg(iTest, 16);
} else {
//String to int conversion error
}

is converting on base32 or base32 but I want that it should convert on base8

Gojir4

@Ayush-Gupta Of course that's another story if you want to handle negative numbers.

QString strIntToHex(const QString &intStr){
    bool ok = false;
    qint32  iTest = intStr.toInt(&ok, 10);
    QString hex;
    if(ok) {
        if(iTest >= INT8_MIN && iTest <= INT8_MAX){
            hex = QString("%1").arg(iTest & 0xFF, 2, 16);
        } else if(iTest >= INT16_MIN && iTest <= INT16_MAX){
            hex = QString("%1").arg(iTest & 0xFFFF, 4, 16);
        } else {
            hex = QString("%1").arg(iTest, 8, 16);
        }
    } else {
       //String to int conversion error
        hex = "error";
    }
    return hex;
}

QString test("65");
qDebug() << strIntToHex("65");
qDebug() << strIntToHex("-23");

return 0;

Output:

"41"
"e9"