how to convert qbytearray to hex array

[Liny]

such as :
qbytearray test;
test[0] = 0x30;
test[1] = 0x31;
qdebug << "test[0] = "<< test[0];
qdebug << "test[1] = "<< test[1];
i want qdebug output:
test[0] = 0x30;
test[1] = 0x31;
not
test[0] = "0x30" or test[0] = "0"
what should i do to get this result?

[mpergand]

@Liny said in how to convert qbytearray to hex array:

test[0] = 0x30;

0x30 is a string representation of a binary value in hexadecimal.

[EDIT]
QByteArray is an array of char.
So test[31] is printed as ascii char 1

To print hex values you can do:
qdebug << hex << "test[1] = "<< test[1];

[Liny]

thanks for your help！

[Liny]

@mpergand
i try this :
qbytearray test;
test[0] = 0x30;
test[1] = 0x31;
qdebug <<"test[0] = "<< hex << test[0];
qdebug <<"test[1] = "<< hex << test[1];
but i get test[0] = 0,test[1] = 1;
why?

[JonB]

@Liny
Try test.toHex() or text.toHex(':').

[mpergand]

@Liny
I forgot the cast !
qDebug() <<hex<< "test[1] = "<< (uint8_t)test[1];

Note the unsigned int.
casting to int, uint or uint8_t don't print the same result:

test[0] = 0x90;
qDebug() <<hex<< "test[0] = "<< (int)test[0] << (uint)test[0]<< (uint8_t)test[0];

test[0] = -70 ffffff90 90

[JonB]

@mpergand said in how to convert qbytearray to hex array:

(uint8_t)test[0]

Why the cast, and why does that change it? I haven't looked, but isn't QByteArray base element type uint8_t, or similar?

[mpergand]

@JonB

char at(int i) const
char operator[](int i) const

they return char, so debug prints ascii char, hence the cast if you want an other type.

[JonB]

@mpergand said in how to convert qbytearray to hex array:

they return char

Oohhh, I thought it would return uint8_t (or unsigned char)! Why signed?!