[Qt-interest] QByteArray containing numbers bigger than 127

[Murphy, Sean M.]

You need to recheck your C++ theory.

 

A "char" is 1 byte

An "int" is 4 bytes

 

A "char" represents -128 to +127

An "unsigned char" represents 0 to +255

 

If you re-wrote your code to say

  unsigned char test = array.at(0)

 

"test" would then equal 200.

 

If you want to push data types other than char/unsigned char, I'd
recommend you look into the << and >> operators for a QDataStream set on
a QByteArray.

 

Sean

 

From: qt-interest-bounces at trolltech.com
[mailto:qt-interest-bounces at trolltech.com] On Behalf Of Patric
Sent: Friday, June 05, 2009 3:46 PM
To: qt-interest at trolltech.com
Subject: [Qt-interest] QByteArray containing numbers bigger than 127

 

Hi all. 

I have QByteArray here with numbers. One of the number is bigger than
127, and it seems I can't correctly extract it... 

My number si 200, but it's extracted as -56. 

 

For example : 

 

QByteArray array;

array.append(200);

int test = array.at(0);

// test - -56 

 

I think that is because at() returns char... 

but isn't that stupid ? After all, it's QByteArray, not QCharArray. It
should return int, not char. 

 

Patric

 



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