QByteArray(3qt)QByteArray(3qt)NAME
QByteArray - Array of bytes
#include <qcstring.h>
Inherits QArray.
Inherited by QBitArray and QCString.
Public Members
QByteArray ()
QByteArray ( int size )
QByteArray ( const QByteArray & a )
~QByteArray ()
QByteArray& operator= ( const QByteArray & a )
char* data () const
uint nrefs () const
uint size () const
uint count () const
bool isEmpty () const
bool isNull () const
bool resize ( uint size )
bool truncate ( uint pos )
bool fill ( const char & d, int size = -1 )
virtual void detach ()
QByteArray copy () const
QByteArray& assign ( const QByteArray & a )
QByteArray& assign ( const char * a, uint n )
QByteArray& duplicate ( const QByteArray & a )
QByteArray& duplicate ( const char * a, uint n )
QByteArray& setRawData ( const char * a, uint n )
void resetRawData ( const char * a, uint n )
int find ( const char & d, uint i=0 ) const
int contains ( const char & d ) const
void sort ()
int bsearch ( const char & d ) const
char& operator[] ( int i ) const
char& at ( uint i ) const
operator const char* ()const
bool operator== ( const QByteArray & a ) const
bool operator!= ( const QByteArray & a ) const
Iterator begin ()
Iterator end ()
ConstIterator begin () const
ConstIterator end () const
Protected Members
QByteArray ( int, int )
RELATED FUNCTION DOCUMENTATION
(Note that these are not member functions.)
Q_UINT16 qChecksum (const char * data, uint len)
QDataStream & operator<< (QDataStream & s, const
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QByteArray(3qt)QByteArray(3qt)
QByteArray & a)
QDataStream & operator>> (QDataStream & s, QByteArray & a)
DESCRIPTION
The QByteArray class provides an array of bytes.
The QByteArray class provides an explicitly shared array
of bytes. It is useful for manipulating memory areas with
custom data. QByteArray is implemented as QArray<char>.
See the QArray documentation for further information.
MEMBER FUNCTION DOCUMENTATIONQByteArray::QByteArray ()
Constructs a null array.
See also isNull().
QByteArray::QByteArray ( const QByteArray & a )
Constructs a shallow copy of a.
See also assign().
QByteArray::QByteArray ( int size )
Constructs an array with room for size elements. Makes a
null array if size == 0.
Note that the elements are not initialized.
See also resize() and isNull().
QByteArray::QByteArray ( int, int ) [protected]
Constructs an array without allocating array space. The
arguments should be (0, 0). Use at own risk.
QByteArray::~QByteArray ()
Dereferences the array data and deletes it if this was the
last reference.
QByteArray::operator const char * () const
Cast operator. Returns a pointer to the array.
See also data().
QByteArray & QByteArray::assign ( const QByteArray & a )
Shallow copy. Dereferences the current array and
references the data contained in a instead. Returns a
reference to this array.
See also operator=().
QByteArray & QByteArray::assign ( const char * data, uint size )
Shallow copy. Dereferences the current array and
references the array data data, which contains size
elements. Returns a reference to this array.
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Do not delete data later, QArray takes care of that.
char & QByteArray::at ( uint index ) const
Returns a reference to the element at position index in
the array.
This can be used to both read and set an element.
See also operator[]().
ConstIterator QByteArray::begin () const
Returns a const iterator pointing at the beginning of this
array. This iterator can be used as the iterators of
QValueList and QMap for example. In fact it does not only
behave like a usual pointer: It is a pointer.
Iterator QByteArray::begin ()
Returns an iterator pointing at the beginning of this
array. This iterator can be used as the iterators of
QValueList and QMap for example. In fact it does not only
behave like a usual pointer: It is a pointer.
int QByteArray::bsearch ( const char & v ) const
In a sorted array, finds the first occurrence of v using
binary search. For a sorted array, this is generally much
faster than find(), which does a linear search.
Returns the position of v, or -1 if v could not be found.
See also sort() and find().
int QByteArray::contains ( const char & v ) const
Returns the number of times v occurs in the array.
See also find().
QByteArray QByteArray::copy () const
Returns a deep copy of this array.
See also detach() and duplicate().
uint QByteArray::count () const
Returns the same as size().
See also size().
char * QByteArray::data () const
Returns a pointer to the actual array data.
The array is a null array if data() == 0 (null pointer).
See also isNull().
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QByteArray(3qt)QByteArray(3qt)void QByteArray::detach () [virtual]
Detaches this array from shared array data, i.e. makes a
private, deep copy of the data.
Copying will only be performed if the reference count is
greater than one.
See also copy().
Reimplemented from QGArray.
QByteArray & QByteArray::duplicate ( const QByteArray & a )
Deep copy. Dereferences the current array and obtains a
copy of the data contained in a instead. Returns a
reference to this array.
See also copy().
QByteArray & QByteArray::duplicate ( const char * data, uint size
)
Deep copy. Dereferences the current array and obtains a
copy of the array data data instead. Returns a reference
to this array.
See also copy().
ConstIterator QByteArray::end () const
Returns a const iterator pointing behind the last element
of this array. This iterator can be used as the iterators
of QValueList and QMap for example. In fact it does not
only behave like a usual pointer: It is a pointer.
Iterator QByteArray::end ()
Returns an iterator pointing behind the last element of
this array. This iterator can be used as the iterators of
QValueList and QMap for example. In fact it does not only
behave like a usual pointer: It is a pointer.
bool QByteArray::fill ( const char & v, int size = -1 )
Fills the array with the value v. If size is specified as
different from -1, then the array will be resized before
filled.
Returns TRUE if successful, or FALSE if the memory cannot
be allocated (only when size != -1).
See also resize().
int QByteArray::find ( const char & v, uint index=0 ) const
Finds the first occurrence of v, starting at position
index.
Returns the position of v, or -1 if v could not be found.
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See also contains().
bool QByteArray::isEmpty () const
Returns TRUE if the array is empty, i.e. size() == 0,
otherwise FALSE.
isEmpty() is equivalent with isNull() for QArray. Note
that this is not the case for QCString::isEmpty().
bool QByteArray::isNull () const
Returns TRUE if the array is null, otherwise FALSE.
A null array has size() == 0 and data() == 0.
uint QByteArray::nrefs () const
Returns the reference count for the shared array data.
This reference count is always greater than zero.
bool QByteArray::operator!= ( const QByteArray & a ) const
Returns TRUE if this array is different from a, otherwise
FALSE.
The two arrays are bitwise compared.
See also operator==().
QByteArray & QByteArray::operator= ( const QByteArray & a )
Assigns a shallow copy of a to this array and returns a
reference to this array.
Equivalent to assign( a ).
bool QByteArray::operator== ( const QByteArray & a ) const
Returns TRUE if this array is equal to a, otherwise FALSE.
The two arrays are bitwise compared.
See also operator!=().
char & QByteArray::operator[] ( int index ) const
Returns a reference to the element at position index in
the array.
This can be used to both read and set an element.
Equivalent to at().
See also at().
void QByteArray::resetRawData ( const char * data, uint size )
Resets raw data that was set using setRawData().
The arguments must be the data and length that were passed
to setRawData(). This is for consistency checking.
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QByteArray(3qt)QByteArray(3qt)
See also setRawData().
bool QByteArray::resize ( uint size )
Resizes (expands or shrinks) the array to size elements.
The array becomes a null array if size == 0.
Returns TRUE if successful, or FALSE if the memory cannot
be allocated.
New elements will not be initialized.
See also size().
QByteArray & QByteArray::setRawData ( const char * data, uint
size )
Sets raw data and returns a reference to the array.
Dereferences the current array and sets the new array data
to data and the new array size to size. Do not attempt to
resize or re-assign the array data when raw data has been
set. Call resetRawData(d,len) to reset the array.
Setting raw data is useful because it sets QArray data
without allocating memory or copying data.
Example I (intended use):
static char bindata[] = { 231, 1, 44, ... };
QByteArray a;
a.setRawData( bindata, sizeof(bindata) ); // a points to bindata
QDataStream s( a, IO_ReadOnly ); // open on a's data
s >> <something>; // read raw bindata
a.resetRawData( bindata, sizeof(bindata) ); // finished
Example II (you don't want to do this):
static char bindata[] = { 231, 1, 44, ... };
QByteArray a, b;
a.setRawData( bindata, sizeof(bindata) ); // a points to bindata
a.resize( 8 ); // will crash
b = a; // will crash
a[2] = 123; // might crash
// forget to resetRawData - will crash
Warning: If you do not call resetRawData(), QArray will
attempt to deallocate or reallocate the raw data, which
might not be too good. Be careful.
See also resetRawData().
uint QByteArray::size () const
Returns the size of the array (max number of elements).
The array is a null array if size() == 0.
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See also isNull() and resize().
void QByteArray::sort ()
Sorts the array elements in ascending order, using bitwise
comparison (memcmp()).
See also bsearch().
bool QByteArray::truncate ( uint pos )
Truncates the array at position pos.
Returns TRUE if successful, or FALSE if the memory cannot
be allocated.
Equivalent to resize(pos).
See also resize().
RELATED FUNCTION DOCUMENTATIONQ_UINT16 qChecksum (const char * data, uint len)
Returns the CRC-16 checksum of len bytes starting at data.
The checksum is independent of the byte order
(endianness).
QDataStream & operator<;< (QDataStream & s, const QByteArray & a)
Writes a byte array to a stream and returns a reference to
the stream.
See also Format of the QDataStream operators
QDataStream & operator>> (QDataStream & s, QByteArray & a)
Reads a byte array from a stream and returns a reference
to the stream.
See also Format of the QDataStream operators
SEE ALSO
http://doc.trolltech.com/qbytearray.html
http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2001 Trolltech AS,
http://www.trolltech.com. See the license file included
in the distribution for a complete license statement.
AUTHOR
Generated automatically from the source code.
BUGS
If you find a bug in Qt, please report it as described in
http://doc.trolltech.com/bughowto.html. Good bug reports
make our job much simpler. Thank you.
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QByteArray(3qt)QByteArray(3qt)
In case of content or formattting problems with this
manual page, please report them to qt-bugs@trolltech.com.
Please include the name of the manual page
(qbytearray.3qt) and the Qt version (2.3.1).
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