source: trunk/doc/src/qiterator.qdoc@ 172

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/*! 
    \class QListIterator
    \inmodule QtCore

    \brief The QListIterator class provides a Java-style const iterator for QList and QQueue.

    QList has both \l{Java-style iterators} and \l{STL-style
    iterators}. The Java-style iterators are more high-level and
    easier to use than the STL-style iterators; on the other hand,
    they are slightly less efficient.

    An alternative to using iterators is to use index positions. Most
    QList member functions take an index as their first parameter,
    making it possible to access, modify, and remove items without
    using iterators.

    QListIterator\<T\> allows you to iterate over a QList\<T\> (or a
    QQueue\<T\>). If you want to modify the list as you iterate over
    it, use QMutableListIterator\<T\> instead.

    The QListIterator constructor takes a QList as argument. After
    construction, the iterator is located at the very beginning of
    the list (before the first item). Here's how to iterate over all
    the elements sequentially:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 0

    The next() function returns the next item in the list and
    advances the iterator. Unlike STL-style iterators, Java-style
    iterators point \e between items rather than directly \e at
    items. The first call to next() advances the iterator to the
    position between the first and second item, and returns the first
    item; the second call to next() advances the iterator to the
    position between the second and third item, and returns the second
    item; and so on.

    \img javaiterators1.png

    Here's how to iterate over the elements in reverse order:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 1

    If you want to find all occurrences of a particular value, use
    findNext() or findPrevious() in a loop.

    Multiple iterators can be used on the same list. If the list is
    modified while a QListIterator is active, the QListIterator will
    continue iterating over the original list, ignoring the modified
    copy.

    \sa QMutableListIterator, QList::const_iterator
*/

/*! 
    \class QLinkedListIterator
    \inmodule QtCore

    \brief The QLinkedListIterator class provides a Java-style const iterator for QLinkedList.

    QLinkedList has both \l{Java-style iterators} and
    \l{STL-style iterators}. The Java-style iterators are more
    high-level and easier to use than the STL-style iterators; on the
    other hand, they are slightly less efficient.

    QLinkedListIterator\<T\> allows you to iterate over a
    QLinkedList\<T\>. If you want to modify the list as you iterate
    over it, use QMutableLinkedListIterator\<T\> instead.

    The QLinkedListIterator constructor takes a QLinkedList as
    argument. After construction, the iterator is located at the very
    beginning of the list (before the first item). Here's how to
    iterate over all the elements sequentially:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 2

    The next() function returns the next item in the list and
    advances the iterator. Unlike STL-style iterators, Java-style
    iterators point \e between items rather than directly \e at
    items. The first call to next() advances the iterator to the
    position between the first and second item, and returns the first
    item; the second call to next() advances the iterator to the
    position between the second and third item, and returns the second
    item; and so on.

    \img javaiterators1.png

    Here's how to iterate over the elements in reverse order:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 3

    If you want to find all occurrences of a particular value, use
    findNext() or findPrevious() in a loop.

    Multiple iterators can be used on the same list. If the list is
    modified while a QLinkedListIterator is active, the
    QLinkedListIterator will continue iterating over the original
    list, ignoring the modified copy.

    \sa QMutableLinkedListIterator, QLinkedList::const_iterator
*/

/*! 
    \class QVectorIterator
    \inmodule QtCore
    \brief The QVectorIterator class provides a Java-style const iterator for QVector and QStack.

    QVector has both \l{Java-style iterators} and \l{STL-style
    iterators}. The Java-style iterators are more high-level and
    easier to use than the STL-style iterators; on the other hand,
    they are slightly less efficient.

    An alternative to using iterators is to use index positions. Most
    QVector member functions take an index as their first parameter,
    making it possible to access, insert, and remove items without
    using iterators.

    QVectorIterator\<T\> allows you to iterate over a QVector\<T\>
    (or a QStack\<T\>). If you want to modify the vector as you
    iterate over it, use QMutableVectorIterator\<T\> instead.

    The QVectorIterator constructor takes a QVector as argument.
    After construction, the iterator is located at the very beginning
    of the vector (before the first item). Here's how to iterate over
    all the elements sequentially:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 4

    The next() function returns the next item in the vector and
    advances the iterator. Unlike STL-style iterators, Java-style
    iterators point \e between items rather than directly \e at
    items. The first call to next() advances the iterator to the
    position between the first and second item, and returns the first
    item; the second call to next() advances the iterator to the
    position between the second and third item, returning the second
    item; and so on.

    \img javaiterators1.png

    Here's how to iterate over the elements in reverse order:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 5

    If you want to find all occurrences of a particular value, use
    findNext() or findPrevious() in a loop.

    Multiple iterators can be used on the same vector. If the vector
    is modified while a QVectorIterator is active, the QVectorIterator
    will continue iterating over the original vector, ignoring the
    modified copy.

    \sa QMutableVectorIterator, QVector::const_iterator
*/

/*! 
    \class QSetIterator
    \inmodule QtCore
    \brief The QSetIterator class provides a Java-style const iterator for QSet.

    QSet supports both \l{Java-style iterators} and \l{STL-style
    iterators}. The Java-style iterators are more high-level and
    easier to use than the STL-style iterators; on the other hand,
    they are slightly less efficient.

    QSetIterator\<T\> allows you to iterate over a QSet\<T\>. If you
    want to modify the set as you iterate over it, use
    QMutableSetIterator\<T\> instead.

    The constructor takes a QSet as argument. After construction, the
    iterator is located at the very beginning of the set (before
    the first item). Here's how to iterate over all the elements
    sequentially:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 6

    The next() function returns the next item in the set and
    advances the iterator. Unlike STL-style iterators, Java-style
    iterators point \e between items rather than directly \e at
    items. The first call to next() advances the iterator to the
    position between the first and second item, and returns the first
    item; the second call to next() advances the iterator to the
    position between the second and third item, returning the second
    item; and so on.

    \img javaiterators1.png

    Here's how to iterate over the elements in reverse order:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 7

    If you want to find all occurrences of a particular value, use
    findNext() or findPrevious() in a loop.

    Multiple iterators can be used on the same set. If the set
    is modified while a QSetIterator is active, the QSetIterator
    will continue iterating over the original set, ignoring the
    modified copy.

    \sa QMutableSetIterator, QSet::const_iterator
*/

/*! 
    \class QMutableListIterator
    \inmodule QtCore

    \brief The QMutableListIterator class provides a Java-style non-const iterator for QList and QQueue.

    QList has both \l{Java-style iterators} and \l{STL-style
    iterators}. The Java-style iterators are more high-level and
    easier to use than the STL-style iterators; on the other hand,
    they are slightly less efficient.

    An alternative to using iterators is to use index positions. Most
    QList member functions take an index as their first parameter,
    making it possible to access, insert, and remove items without
    using iterators.

    QMutableListIterator\<T\> allows you to iterate over a QList\<T\>
    (or a QQueue\<T\>) and modify the list. If you don't want to
    modify the list (or have a const QList), use the slightly faster
    QListIterator\<T\> instead.

    The QMutableListIterator constructor takes a QList as argument.
    After construction, the iterator is located at the very beginning
    of the list (before the first item). Here's how to iterate over
    all the elements sequentially:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 8

    The next() function returns the next item in the list and
    advances the iterator. Unlike STL-style iterators, Java-style
    iterators point \e between items rather than directly \e at
    items. The first call to next() advances the iterator to the
    position between the first and second item, and returns the first
    item; the second call to next() advances the iterator to the
    position between the second and third item, returning the second
    item; and so on.

    \img javaiterators1.png

    Here's how to iterate over the elements in reverse order:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 9

    If you want to find all occurrences of a particular value, use
    findNext() or findPrevious() in a loop.

    If you want to remove items as you iterate over the list, use
    remove(). If you want to modify the value of an item, use
    setValue(). If you want to insert a new item in the list, use
    insert().

    Example:
    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 10

    The example traverses a list, replacing negative numbers with
    their absolute values, and eliminating zeroes.

    Only one mutable iterator can be active on a given list at any
    time. Furthermore, no changes should be done directly to the list
    while the iterator is active (as opposed to through the
    iterator), since this could invalidate the iterator and lead to
    undefined behavior.

    \sa QListIterator, QList::iterator
*/

/*! 
    \class QMutableLinkedListIterator
    \inmodule QtCore

    \brief The QMutableLinkedListIterator class provides a Java-style non-const iterator for QLinkedList.

    QLinkedList has both \l{Java-style iterators} and
    \l{STL-style iterators}. The Java-style iterators are more
    high-level and easier to use than the STL-style iterators; on the
    other hand, they are slightly less efficient.

    QMutableLinkedListIterator\<T\> allows you to iterate over a
    QLinkedList\<T\> and modify the list. If you don't want to modify
    the list (or have a const QLinkedList), use the slightly faster
    QLinkedListIterator\<T\> instead.

    The QMutableLinkedListIterator constructor takes a QLinkedList as
    argument. After construction, the iterator is located at the very
    beginning of the list (before the first item). Here's how to
    iterate over all the elements sequentially:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 11

    The next() function returns the next item in the list and
    advances the iterator. Unlike STL-style iterators, Java-style
    iterators point \e between items rather than directly \e at
    items. The first call to next() advances the iterator to the
    position between the first and second item, and returns the first
    item; the second call to next() advances the iterator to the
    position between the second and third item, returning the second
    item; and so on.

    \img javaiterators1.png

    Here's how to iterate over the elements in reverse order:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 12

    If you want to find all occurrences of a particular value, use
    findNext() or findPrevious() in a loop.

    If you want to remove items as you iterate over the list, use
    remove(). If you want to modify the value of an item, use
    setValue(). If you want to insert a new item in the list, use
    insert().

    Example:
    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 13

    The example traverses a list, replacing negative numbers with
    their absolute values, and eliminating zeroes.

    Only one mutable iterator can be active on a given list at any
    time. Furthermore, no changes should be done directly to the list
    while the iterator is active (as opposed to through the
    iterator), since this could invalidate the iterator and lead to
    undefined behavior.

    \sa QLinkedListIterator, QLinkedList::iterator
*/

/*! 
    \class QMutableVectorIterator
    \inmodule QtCore

    \brief The QMutableVectorIterator class provides a Java-style non-const iterator for QVector and QStack.

    QVector has both \l{Java-style iterators} and \l{STL-style
    iterators}. The Java-style iterators are more high-level and
    easier to use than the STL-style iterators; on the other hand,
    they are slightly less efficient.

    An alternative to using iterators is to use index positions. Most
    QVector member functions take an index as their first parameter,
    making it possible to access, insert, and remove items without
    using iterators.

    QMutableVectorIterator\<T\> allows you to iterate over a
    QVector\<T\> and modify the vector. If you don't want to modify
    the vector (or have a const QVector), use the slightly faster
    QVectorIterator\<T\> instead.

    The QMutableVectorIterator constructor takes a QVector as
    argument. After construction, the iterator is located at the very
    beginning of the list (before the first item). Here's how to
    iterate over all the elements sequentially:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 14

    The next() function returns the next item in the vector and
    advances the iterator. Unlike STL-style iterators, Java-style
    iterators point \e between items rather than directly \e at
    items. The first call to next() advances the iterator to the
    position between the first and second item, and returns the first
    item; the second call to next() advances the iterator to the
    position between the second and third item, returning the second
    item; and so on.

    \img javaiterators1.png

    Here's how to iterate over the elements in reverse order:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 15

    If you want to find all occurrences of a particular value, use
    findNext() or findPrevious() in a loop.

    If you want to remove items as you iterate over the vector, use
    remove(). If you want to modify the value of an item, use
    setValue(). If you want to insert a new item in the vector, use
    insert().

    Example:
    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 16

    The example traverses a vector, replacing negative numbers with
    their absolute values, and eliminating zeroes.

    Only one mutable iterator can be active on a given vector at any
    time. Furthermore, no changes should be done directly to the
    vector while the iterator is active (as opposed to through the
    iterator), since this could invalidate the iterator and lead to
    undefined behavior.

    \sa QVectorIterator, QVector::iterator
*/

/*! 
    \class QMutableSetIterator
    \inmodule QtCore
    \since 4.2

    \brief The QMutableSetIterator class provides a Java-style non-const iterator for QSet.

    QSet has both \l{Java-style iterators} and \l{STL-style
    iterators}. The Java-style iterators are more high-level and
    easier to use than the STL-style iterators; on the other hand,
    they are slightly less efficient.

    QMutableSetIterator\<T\> allows you to iterate over a QSet\<T\>
    and remove items from the set as you iterate. If you don't want
    to modify the set (or have a const QSet), use the slightly faster
    QSetIterator\<T\> instead.

    The QMutableSetIterator constructor takes a QSet as argument.
    After construction, the iterator is located at the very beginning
    of the set (before the first item). Here's how to iterate over
    all the elements sequentially:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 17

    The next() function returns the next item in the set and
    advances the iterator. Unlike STL-style iterators, Java-style
    iterators point \e between items rather than directly \e at
    items. The first call to next() advances the iterator to the
    position between the first and second item, and returns the first
    item; the second call to next() advances the iterator to the
    position between the second and third item, returning the second
    item; and so on.

    \img javaiterators1.png

    Here's how to iterate over the elements in reverse order:

    \snippet doc/src/snippets/code/doc_src_qiterator.qdoc 18

    If you want to remove items as you iterate over the set, use
    remove().

    Only one mutable iterator can be active on a given set at any
    time. Furthermore, no changes should be done directly to the set
    while the iterator is active (as opposed to through the
    iterator), since this could invalidate the iterator and lead to