+- 0Day Forums (https://0day.red)
+-- Forum: Coding (https://0day.red/Forum-Coding)
+--- Forum: C & C++ (https://0day.red/Forum-C-C)
+--- Thread: Convert from float to QByteArray (/Thread-Convert-from-float-to-QByteArray)
Convert from float to QByteArray - anitaaauycluz - 07-26-2023
Is there a quick way to convert a float value to a byte wise (hex) representation in a `QByteArray`?
Have done similar with `memcpy()` before using arrays, but this doesn't seem to work too well with `QByteArray`.
For example:
memcpy(&byteArrayData,&floatData,sizeof(float));
Can go the other way just fine using:
float *value= (float *)byteArrayData.data();
Am I just implementing this wrong or is there a better way to do it using Qt?
Thanks
RE: Convert from float to QByteArray - defeaturesongxurhtc - 07-26-2023
I'm not sure what you want exactly.
To stuff the binary representation into a QByteArray you can use this:
float f = 0.0f;
QByteArray ba(reinterpret_cast<const char *>(&f), sizeof (f));
To get a hex representation of the float you can add this:
QByteArray baHex = ba.toHex();
RE: Convert from float to QByteArray - croquette937 - 07-26-2023
From the [QByteArray Class Reference][1] page:
float f = 0.0f;
QByteArray array(reinterpret_cast<const char*>(&f), sizeof(f));
Will initialize a `QByteArray` with the memory content of the float stored in it.
If you already have one and just want to append the data to it:
array.append(reinterpret_cast<const char*>(&f), sizeof(f));
Should do it as well.
To go the other way around, you just have to perform the reverse operation:
float f2;
if (array.size() >= sizeof(f2)
{
f2 = *reinterpret_cast<const float*>(array.data());
} else
{
// The array is not big enough.
}
[1]:
[To see links please register here]
[2]:[To see links please register here]