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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>QMapIterator Class Reference</h1><br clear="all">
<p>
The QMapIterator class provides an iterator for <a href="qmap.html">QMap</a>.
<a href="#details">More...</a>
<p>
<code>#include <<a href="qmap-h.html">qmap.h</a>></code>
<p><a href="qmapiterator-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li><div class="fn"><a href="#61336e"><b>QMapIterator</b></a>()</div>
<li><div class="fn"><a href="#eaf4f5"><b>QMapIterator</b></a>(QMapNode<K, T>*p)</div>
<li><div class="fn"><a href="#ddb52f"><b>QMapIterator</b></a>(constQMapIterator<K,T>&it)</div>
<li><div class="fn">bool<a href="#dd06b8"><b>operator==</b></a>(constQMapIterator<K,T>&it)const</div>
<li><div class="fn">bool<a href="#ddfd65"><b>operator!=</b></a>(constQMapIterator<K,T>&it)const</div>
<li><div class="fn">T&<a href="#57a1c9"><b>operator*</b></a>()</div>
<li><div class="fn">constT&<a href="#c66e69"><b>operator*</b></a>()const</div>
<li><div class="fn">constK&<a href="#6639c3"><b>key</b></a>()const</div>
<li><div class="fn">T&<a href="#f7b448"><b>data</b></a>()</div>
<li><div class="fn">constT&<a href="#78950a"><b>data</b></a>()const</div>
</ul>
<hr><h2><a name="details"></a>Detailed Description</h2>
The QMapIterator class provides an iterator for <a href="qmap.html">QMap</a>.
<p>
You can not create an iterator by yourself. Instead you have to ask
a map to give you one. An iterator has only the size of a pointer.
On 32 bit machines that means 4 bytes otherwise 8 bytes. That makes
them very fast. In fact they resemble the semantics of pointers as
good as possible and they are almost as fast as usual pointers.
<p>Example:
<pre> #include <qmap.h>
#include <qstring.h>
#include <stdio.h>
class Employee
{
public:
Employee(): s(0) {}
Employee( const QString& name, int salary )
: n(name), s(salary)
{}
<a href="qstring.html">QString</a> name() const { return n; }
int salary() const { return s; }
void setSalary( int salary ) { s = salary; }
private:
<a href="qstring.html">QString</a> n;
int s;
};
void main()
{
typedef QMap<<a href="qstring.html">QString</a>,Employee> EmployeeMap;
EmployeeMap map; // map of Employee
map.insert( "Gates", Employee("Bill", 50000) );
map.insert( "Ballmer", Employee("Steve",80000) );
map.insert( "Sommer,", Employee("Ron", 60000) );
Employee joe( "Joe", 50000 );
map.insert( "Doe", joe );
joe.setSalary( 4000 );
EmployeeMap::Iterator it;
for( it = map.begin(); it != map.end(); ++it )
printf( "%s, %s earns %d\n", it.key().latin1(), it.data().name().latin1(), it.data().salary() );
}
</pre>
<p>Program output:
<pre> Ballmer, Steve earns 80000
Doe, Joe earns 50000
Gates, Bill earns 50000
Sommer, Ron earns 60000
</pre>
<p>The only way to traverse a map is to use iterators. QMap is highly
optimized for performance and memory usage. On the other hand that
means that you have to be a bit more careful by what you are
doing. QMap does not know about all its iterators and the iterators
don't even know to which map they belong. That makes things fast and
slim but a bit dangerous because it is up to you to make sure that
iterators you are using are still valid. <a href="qdictiterator.html">QDictIterator</a> will be able
to give warnings while QMapIterator may end up in an undefined
state.
<p>For every Iterator there is a ConstIterator. When accessing a QMap
in a const environment or if the reference or pointer to the map is
itself const, then you have to use the ConstIterator. Its semantics
are the same, but it returns only const references to the item it
points to.
<p>See also <a href="qmap.html">QMap</a>.
<hr><h2>Member Function Documentation</h2>
<h3 class="fn"><a name="61336e"></a>QMapIterator::QMapIterator()</h3>
<p>Creates an uninitialized iterator.
<h3 class="fn"><a name="eaf4f5"></a>QMapIterator::QMapIterator(QMapNode<K, T>*p)</h3>
<p>Constructs an iterator starting at node <em>p.</em>
<h3 class="fn"><a name="ddb52f"></a>QMapIterator::QMapIterator(constQMapIterator<K,T>&it)</h3>
<p>Constructs a copy of the iterator.
<h3 class="fn">T&<a name="f7b448"></a>QMapIterator::data()</h3>
<p>Returns a reference to the current item.
<h3 class="fn">constT&<a name="78950a"></a>QMapIterator::data()const</h3>
<p>Returns a const reference to the data of the current item.
<h3 class="fn">constK&<a name="6639c3"></a>QMapIterator::key()const</h3>
<p>Returns a const reference to the data of the current key.
<h3 class="fn">bool<a name="ddfd65"></a>QMapIterator::operator!=(constQMapIterator<K,T>&it)const</h3>
<p>Compares both iterators and returns TRUE if they point to different
items.
<h3 class="fn">T&<a name="57a1c9"></a>QMapIterator::operator*()</h3>
<p>Asterix operator. Returns a reference to the current item. The same
as <a href="#78950a">data</a>().
<h3 class="fn">constT&<a name="c66e69"></a>QMapIterator::operator*()const</h3>
<p>Asterix operator. Returns a const reference to the current item. The
same as <a href="#78950a">data</a>().
<h3 class="fn">bool<a name="dd06b8"></a>QMapIterator::operator==(constQMapIterator<K,T>&it)const</h3>
<p>Compares both iterators and returns TRUE if they point to the same
item.
<hr><p>
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