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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
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<h1 align=center>QByteArray Class Reference</h1><br clear="all">
<p>
The QByteArray class provides an array of bytes.
<a href="#details">More...</a>
<p>
<code>#include <<a href="qcstring-h.html">qcstring.h</a>></code>
<p>
Inherits <a href="qarray.html">QArray</a>.
<p>Inherited by <a href="qbitarray.html">QBitArray</a> and <a href="qcstring.html">QCString</a>.
<p><a href="qbytearray-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li><div class="fn"><a href="#fd22d8"><b>QByteArray</b></a>()</div>
<li><div class="fn"><a href="#2075a2"><b>QByteArray</b></a>(intsize)</div>
<li><div class="fn"><a href="#dc546a"><b>QByteArray</b></a>(constQByteArray&a)</div>
<li><div class="fn"><a href="#62fd99"><b>~QByteArray</b></a>()</div>
<li><div class="fn">QByteArray&<a href="#bdbf15"><b>operator=</b></a>(constQByteArray&a)</div>
<li><div class="fn">char*<a href="#2733f4"><b>data</b></a>()const</div>
<li><div class="fn">uint<a href="#85f580"><b>nrefs</b></a>()const</div>
<li><div class="fn">uint<a href="#3d2edb"><b>size</b></a>()const</div>
<li><div class="fn">uint<a href="#48b0b8"><b>count</b></a>()const</div>
<li><div class="fn">bool<a href="#283277"><b>isEmpty</b></a>()const</div>
<li><div class="fn">bool<a href="#0b22bc"><b>isNull</b></a>()const</div>
<li><div class="fn">bool<a href="#191333"><b>resize</b></a>(uintsize)</div>
<li><div class="fn">bool<a href="#9ddc3b"><b>truncate</b></a>(uintpos)</div>
<li><div class="fn">bool<a href="#c8bd6a"><b>fill</b></a>(constchar&d, intsize=-1)</div>
<li><div class="fn">virtualvoid<a href="#57e5a9"><b>detach</b></a>()</div>
<li><div class="fn">QByteArray<a href="#f38609"><b>copy</b></a>()const</div>
<li><div class="fn">QByteArray&<a href="#762155"><b>assign</b></a>(constQByteArray&a)</div>
<li><div class="fn">QByteArray&<a href="#85f019"><b>assign</b></a>(constchar*a, uintn)</div>
<li><div class="fn">QByteArray&<a href="#c84f0c"><b>duplicate</b></a>(constQByteArray&a)</div>
<li><div class="fn">QByteArray&<a href="#8381c1"><b>duplicate</b></a>(constchar*a, uintn)</div>
<li><div class="fn">QByteArray&<a href="#69921b"><b>setRawData</b></a>(constchar*a, uintn)</div>
<li><div class="fn">void<a href="#756c99"><b>resetRawData</b></a>(constchar*a, uintn)</div>
<li><div class="fn">int<a href="#6c988e"><b>find</b></a>(constchar&d, uinti=0)const</div>
<li><div class="fn">int<a href="#cf9407"><b>contains</b></a>(constchar&d)const</div>
<li><div class="fn">void<a href="#fd26e9"><b>sort</b></a>()</div>
<li><div class="fn">int<a href="#1affad"><b>bsearch</b></a>(constchar&d)const</div>
<li><div class="fn">char&<a href="#5204c2"><b>operator[]</b></a>(inti)const</div>
<li><div class="fn">char&<a href="#d5c183"><b>at</b></a>(uinti)const</div>
<li><div class="fn">operator<a href=qbytearray.html#7a38b7><b>constchar*</b></a>()const</div>
<li><div class="fn">bool<a href="#8b105a"><b>operator==</b></a>(constQByteArray&a)const</div>
<li><div class="fn">bool<a href="#31b8f2"><b>operator!=</b></a>(constQByteArray&a)const</div>
<li><div class="fn">Iterator<a href="#470147"><b>begin</b></a>()</div>
<li><div class="fn">Iterator<a href="#e606da"><b>end</b></a>()</div>
<li><div class="fn">ConstIterator<a href="#d1c4b2"><b>begin</b></a>()const</div>
<li><div class="fn">ConstIterator<a href="#1167f8"><b>end</b></a>()const</div>
</ul>
<h2>Protected Members</h2>
<ul>
<li><div class="fn"><a href="#8b482d"><b>QByteArray</b></a>(int, int)</div>
</ul>
<h2>Related Functions</h2>
(Note that these are not member functions.)
<ul>
<li>QDataStream & <a href="qbytearray.html#3a304c"><b>operator>></b></a> (QDataStream & s, QByteArray & a)
<li>QDataStream & <a href="qbytearray.html#e38eb2"><b>operator<<</b></a> (QDataStream & s, const QByteArray & a)
<li>Q_UINT16 <a href="qbytearray.html#f1608b"><b>qChecksum</b></a> (const char * data, uint len)
</ul>
<hr><h2><a name="details"></a>Detailed Description</h2>
The QByteArray class provides an array of bytes.
<p>
The QByteArray class provides an explicitly shared array of
bytes. It is useful for manipulating memory areas with custom
data. QByteArray is implemented as <a href="qarray.html">QArray</a><char>. See the QArray
documentation for further information.
<hr><h2>Member Function Documentation</h2>
<h3 class="fn"><a name="fd22d8"></a>QByteArray::QByteArray()</h3>
<p>Constructs a null array.
<p>See also <a href="#0b22bc">isNull</a>().
<h3 class="fn"><a name="dc546a"></a>QByteArray::QByteArray(constQByteArray&a)</h3>
<p>Constructs a shallow copy of <em>a.</em>
<p>See also <a href="#762155">assign</a>().
<h3 class="fn"><a name="2075a2"></a>QByteArray::QByteArray(intsize)</h3>
<p>Constructs an array with room for <em>size</em> elements.
Makes a null array if <em>size</em> == 0.
<p>Note that the elements are not initialized.
<p>See also <a href="#191333">resize</a>() and <a href="#0b22bc">isNull</a>().
<h3 class="fn"><a name="8b482d"></a>QByteArray::QByteArray(int, int) <code>[protected]</code></h3>
<p>Constructs an array <em>without allocating</em> array space.
The arguments should be (0, 0). Use at own risk.
<h3 class="fn"><a name="62fd99"></a>QByteArray::~QByteArray()</h3>
<p>Dereferences the array data and deletes it if this was the last
reference.
<h3 class="fn"><a name="7a38b7"></a>QByteArray::operatorconstchar*()const</h3>
<p>Cast operator. Returns a pointer to the array.
<p>See also <a href="#2733f4">data</a>().
<h3 class="fn">QByteArray&<a name="762155"></a>QByteArray::assign(constQByteArray&a)</h3>
<p>Shallow copy. Dereferences the current array and references the data
contained in <em>a</em> instead. Returns a reference to this array.
<p>See also <a href="#bdbf15">operator=</a>().
<h3 class="fn">QByteArray&<a name="85f019"></a>QByteArray::assign(constchar*data, uintsize)</h3>
<p>Shallow copy. Dereferences the current array and references the
array data <em>data,</em> which contains <em>size</em> elements.
Returns a reference to this array.
<p>Do not delete <em>data</em> later, <a href="qarray.html">QArray</a> takes care of that.
<h3 class="fn">char&<a name="d5c183"></a>QByteArray::at(uintindex)const</h3>
<p>Returns a reference to the element at position <em>index</em> in the array.
<p>This can be used to both read and set an element.
<p>See also <a href="#5204c2">operator[]</a>().
<h3 class="fn">ConstIterator<a name="d1c4b2"></a>QByteArray::begin()const</h3>
<p>Returns a const iterator pointing at the beginning of this array.
This iterator can be used as the iterators of <a href="qvaluelist.html">QValueList</a> and <a href="qmap.html">QMap</a>
for example. In fact it does not only behave like a usual pointer:
It is a pointer.
<h3 class="fn">Iterator<a name="470147"></a>QByteArray::begin()</h3>
<p>Returns an iterator pointing at the beginning of this array.
This iterator can be used as the iterators of <a href="qvaluelist.html">QValueList</a> and <a href="qmap.html">QMap</a>
for example. In fact it does not only behave like a usual pointer:
It is a pointer.
<h3 class="fn">int<a name="1affad"></a>QByteArray::bsearch(constchar&v)const</h3>
<p>In a sorted array, finds the first occurrence of <em>v</em> using binary
search. For a sorted array, this is generally much faster than
<a href="#6c988e">find</a>(), which does a linear search.
<p>Returns the position of <em>v,</em> or -1 if <em>v</em> could not be found.
<p>See also <a href="#fd26e9">sort</a>() and <a href="#6c988e">find</a>().
<h3 class="fn">int<a name="cf9407"></a>QByteArray::contains(constchar&v)const</h3>
<p>Returns the number of times <em>v</em> occurs in the array.
<p>See also <a href="#6c988e">find</a>().
<h3 class="fn">QByteArray<a name="f38609"></a>QByteArray::copy()const</h3>
<p>Returns a deep copy of this array.
<p>See also <a href="#57e5a9">detach</a>() and <a href="#8381c1">duplicate</a>().
<h3 class="fn">uint<a name="48b0b8"></a>QByteArray::count()const</h3>
<p>Returns the same as <a href="#3d2edb">size</a>().
<p>See also <a href="#3d2edb">size</a>().
<h3 class="fn">char*<a name="2733f4"></a>QByteArray::data()const</h3>
<p>Returns a pointer to the actual array data.
<p>The array is a null array if data() == 0 (null pointer).
<p>See also <a href="#0b22bc">isNull</a>().
<h3 class="fn">void<a name="57e5a9"></a>QByteArray::detach() <code>[virtual]</code></h3>
<p>Detaches this array from shared array data, i.e. makes a private, deep
copy of the data.
<p>Copying will only be performed if the
<a href="#85f580">reference count</a> is greater than one.
<p>See also <a href="#f38609">copy</a>().
<p>Reimplemented from <a href="qgarray.html#66cfb1">QGArray.</a>
<h3 class="fn">QByteArray&<a name="c84f0c"></a>QByteArray::duplicate(constQByteArray&a)</h3>
<p>Deep copy. Dereferences the current array and obtains a copy of the data
contained in <em>a</em> instead. Returns a reference to this array.
<p>See also <a href="#f38609">copy</a>().
<h3 class="fn">QByteArray&<a name="8381c1"></a>QByteArray::duplicate(constchar*data, uintsize)</h3>
<p>Deep copy. Dereferences the current array and obtains a copy of the
array data <em>data</em> instead. Returns a reference to this array.
<p>See also <a href="#f38609">copy</a>().
<h3 class="fn">ConstIterator<a name="1167f8"></a>QByteArray::end()const</h3>
<p>Returns a const iterator pointing behind the last element of this array.
This iterator can be used as the iterators of <a href="qvaluelist.html">QValueList</a> and <a href="qmap.html">QMap</a>
for example. In fact it does not only behave like a usual pointer:
It is a pointer.
<h3 class="fn">Iterator<a name="e606da"></a>QByteArray::end()</h3>
<p>Returns an iterator pointing behind the last element of this array.
This iterator can be used as the iterators of <a href="qvaluelist.html">QValueList</a> and <a href="qmap.html">QMap</a>
for example. In fact it does not only behave like a usual pointer:
It is a pointer.
<h3 class="fn">bool<a name="c8bd6a"></a>QByteArray::fill(constchar&v, intsize=-1)</h3>
<p>Fills the array with the value <em>v.</em> If <em>size</em> is specified as different
from -1, then the array will be resized before filled.
<p>Returns TRUE if successful, or FALSE if the memory cannot be allocated
(only when <em>size</em> != -1).
<p>See also <a href="#191333">resize</a>().
<h3 class="fn">int<a name="6c988e"></a>QByteArray::find(constchar&v, uintindex=0)const</h3>
<p>Finds the first occurrence of <em>v,</em> starting at position <em>index.</em>
<p>Returns the position of <em>v,</em> or -1 if <em>v</em> could not be found.
<p>See also <a href="#cf9407">contains</a>().
<h3 class="fn">bool<a name="283277"></a>QByteArray::isEmpty()const</h3>
<p>Returns TRUE if the array is empty, i.e. <a href="#3d2edb">size</a>() == 0, otherwise FALSE.
<p>isEmpty() is equivalent with <a href="#0b22bc">isNull</a>() for <a href="qarray.html">QArray</a>. Note that this is not
the case for <a href="qcstring.html#93b5d4">QCString::isEmpty</a>().
<h3 class="fn">bool<a name="0b22bc"></a>QByteArray::isNull()const</h3>
<p>Returns TRUE if the array is null, otherwise FALSE.
<p>A null array has <a href="#3d2edb">size</a>() == 0 and <a href="#2733f4">data</a>() == 0.
<h3 class="fn">uint<a name="85f580"></a>QByteArray::nrefs()const</h3>
<p>Returns the reference count for the shared array data. This reference count
is always greater than zero.
<h3 class="fn">bool<a name="31b8f2"></a>QByteArray::operator!=(constQByteArray&a)const</h3>
<p>Returns TRUE if this array is different from <em>a,</em> otherwise FALSE.
<p>The two arrays are bitwise compared.
<p>See also <a href="#8b105a">operator==</a>().
<h3 class="fn">QByteArray&<a name="bdbf15"></a>QByteArray::operator=(constQByteArray&a)</h3>
<p>Assigns a shallow copy of <em>a</em> to this array and returns a reference
to this array.
<p>Equivalent to <a href="#762155">assign</a>( a ).
<h3 class="fn">bool<a name="8b105a"></a>QByteArray::operator==(constQByteArray&a)const</h3>
<p>Returns TRUE if this array is equal to <em>a,</em> otherwise FALSE.
<p>The two arrays are bitwise compared.
<p>See also <a href="#31b8f2">operator!=</a>().
<h3 class="fn">char&<a name="5204c2"></a>QByteArray::operator[](intindex)const</h3>
<p>Returns a reference to the element at position <em>index</em> in the array.
<p>This can be used to both read and set an element. Equivalent to <a href="#d5c183">at</a>().
<p>See also <a href="#d5c183">at</a>().
<h3 class="fn">void<a name="756c99"></a>QByteArray::resetRawData(constchar*data, uintsize)</h3>
<p>Resets raw data that was set using <a href="#69921b">setRawData</a>().
<p>The arguments must be the data and length that were passed to
setRawData(). This is for consistency checking.
<p>See also <a href="#69921b">setRawData</a>().
<h3 class="fn">bool<a name="191333"></a>QByteArray::resize(uintsize)</h3>
<p>Resizes (expands or shrinks) the array to <em>size</em> elements. The array
becomes a null array if <em>size</em> == 0.
<p>Returns TRUE if successful, or FALSE if the memory cannot be allocated.
<p>New elements will not be initialized.
<p>See also <a href="#3d2edb">size</a>().
<h3 class="fn">QByteArray&<a name="69921b"></a>QByteArray::setRawData(constchar*data, uintsize)</h3>
<p>Sets raw data and returns a reference to the array.
<p>Dereferences the current array and sets the new array data to <em>data</em> and
the new array size to <em>size.</em> Do not attempt to resize or re-assign the
array data when raw data has been set.
Call <a href="#756c99">resetRawData</a>(d,len) to reset the array.
<p>Setting raw data is useful because it sets <a href="qarray.html">QArray</a> data without allocating
memory or copying data.
<p>Example I (intended use):
<pre> static char bindata[] = { 231, 1, 44, ... };
<a href="qbytearray.html">QByteArray</a> a;
a.<a href="#69921b">setRawData</a>( bindata, sizeof(bindata) ); // a points to bindata
<a href="qdatastream.html">QDataStream</a> s( a, IO_ReadOnly ); // open on a's data
s >> <something>; // read raw bindata
a.<a href="#756c99">resetRawData</a>( bindata, sizeof(bindata) ); // finished
</pre>
<p>Example II (you don't want to do this):
<pre> static char bindata[] = { 231, 1, 44, ... };
<a href="qbytearray.html">QByteArray</a> a, b;
a.<a href="#69921b">setRawData</a>( bindata, sizeof(bindata) ); // a points to bindata
a.<a href="#191333">resize</a>( 8 ); // will crash
b = a; // will crash
a[2] = 123; // might crash
// forget to resetRawData - will crash
</pre>
<p><b>Warning:</b> If you do not call resetRawData(), QArray will attempt to
deallocate or reallocate the raw data, which might not be too good.
Be careful.
<p>See also <a href="#756c99">resetRawData</a>().
<h3 class="fn">uint<a name="3d2edb"></a>QByteArray::size()const</h3>
<p>Returns the size of the array (max number of elements).
<p>The array is a null array if size() == 0.
<p>See also <a href="#0b22bc">isNull</a>() and <a href="#191333">resize</a>().
<h3 class="fn">void<a name="fd26e9"></a>QByteArray::sort()</h3>
<p>Sorts the array elements in ascending order, using bitwise
comparison (memcmp()).
<p>See also <a href="#1affad">bsearch</a>().
<h3 class="fn">bool<a name="9ddc3b"></a>QByteArray::truncate(uintpos)</h3>
<p>Truncates the array at position <em>pos.</em>
<p>Returns TRUE if successful, or FALSE if the memory cannot be allocated.
<p>Equivalent to <a href="#191333">resize</a>(<em>pos).</em>
<p>See also <a href="#191333">resize</a>().
<hr><h2>Related Functions</h2>
<h3><a href="qdatastream.html">QDataStream</a> & <a name="3a304c"></a>operator>> (<a href="qdatastream.html">QDataStream</a> & s, QByteArray & a)</h3>
<p>Reads a byte array from a stream and returns a reference to the stream.
<p>See also <a href="datastreamformat.html">Format of the QDataStream operators</a>
<h3><a href="qdatastream.html">QDataStream</a> & <a name="e38eb2"></a>operator<< (<a href="qdatastream.html">QDataStream</a> & s, const QByteArray & a)</h3>
<p>Writes a byte array to a stream and returns a reference to the stream.
<p>See also <a href="datastreamformat.html">Format of the QDataStream operators</a>
<h3>Q_UINT16 <a name="f1608b"></a>qChecksum (const char * data, uint len)</h3>
<p>Returns the CRC-16 checksum of <em>len</em> bytes starting at <em>data.</em>
<p>The checksum is independent of the byte order (endianness).
<hr><p>
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