/**************************************************************************** ** ** Copyright (C) 2015 The Qt Company Ltd. ** Contact: http://www.qt.io/licensing/ ** ** This file is part of the documentation of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** You may use this file under the terms of the BSD license as follows: ** ** "Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions are ** met: ** * Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** * Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** * Neither the name of The Qt Company Ltd and its Subsidiary(-ies) nor the ** names of its contributors may be used to endorse or promote products ** derived from this software without specific prior written permission. ** ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/ //! [0] class Employee { public: Employee() {} Employee(const Employee &other); Employee &operator=(const Employee &other); private: QString myName; QDate myDateOfBirth; }; //! [0] //! [1] QList list; list << "A" << "B" << "C" << "D"; QListIterator i(list); while (i.hasNext()) qDebug() << i.next(); //! [1] //! [2] QListIterator i(list); i.toBack(); while (i.hasPrevious()) qDebug() << i.previous(); //! [2] //! [3] QMutableListIterator i(list); while (i.hasNext()) { if (i.next() % 2 != 0) i.remove(); } //! [3] //! [4] QMutableListIterator i(list); i.toBack(); while (i.hasPrevious()) { if (i.previous() % 2 != 0) i.remove(); } //! [4] //! [5] QMutableListIterator i(list); while (i.hasNext()) { if (i.next() > 128) i.setValue(128); } //! [5] //! [6] QMutableListIterator i(list); while (i.hasNext()) i.next() *= 2; //! [6] //! [7] QMap map; map.insert("Paris", "France"); map.insert("Guatemala City", "Guatemala"); map.insert("Mexico City", "Mexico"); map.insert("Moscow", "Russia"); ... QMutableMapIterator i(map); while (i.hasNext()) { if (i.next().key().endsWith("City")) i.remove(); } //! [7] //! [8] QMap map; QHash hash; QMapIterator i(map); while (i.hasNext()) { i.next(); hash.insert(i.key(), i.value()); } //! [8] //! [9] QMutableMapIterator i(map); while (i.findNext(widget)) i.remove(); //! [9] //! [10] QList list; list << "A" << "B" << "C" << "D"; QList::iterator i; for (i = list.begin(); i != list.end(); ++i) *i = (*i).toLower(); //! [10] //! [11] QList list; list << "A" << "B" << "C" << "D"; QList::iterator i = list.end(); while (i != list.begin()) { --i; *i = (*i).toLower(); } //! [11] //! [12] QList::const_iterator i; for (i = list.constBegin(); i != list.constEnd(); ++i) qDebug() << *i; //! [12] //! [13] QMap map; ... QMap::const_iterator i; for (i = map.constBegin(); i != map.constEnd(); ++i) qDebug() << i.key() << ":" << i.value(); //! [13] //! [14] // RIGHT const QList sizes = splitter->sizes(); QList::const_iterator i; for (i = sizes.begin(); i != sizes.end(); ++i) ... // WRONG QList::const_iterator i; for (i = splitter->sizes().begin(); i != splitter->sizes().end(); ++i) ... //! [14] //! [15] QLinkedList list; ... QString str; foreach (str, list) qDebug() << str; //! [15] //! [16] QLinkedList list; ... QLinkedListIterator i(list); while (i.hasNext()) qDebug() << i.next(); //! [16] //! [17] QLinkedList list; ... foreach (const QString &str, list) qDebug() << str; //! [17] //! [18] QLinkedList list; ... foreach (const QString &str, list) { if (str.isEmpty()) break; qDebug() << str; } //! [18] //! [19] QMap map; ... foreach (const QString &str, map.keys()) qDebug() << str << ":" << map.value(str); //! [19] //! [20] QMultiMap map; ... foreach (const QString &str, map.uniqueKeys()) { foreach (int i, map.values(str)) qDebug() << str << ":" << i; } //! [20] //! [21] forever { ... } //! [21] //! [22] CONFIG += no_keywords //! [22] //! [23] QString onlyLetters(const QString &in) { QString out; for (int j = 0; j < in.size(); ++j) { if (in[j].isLetter()) out += in[j]; } return out; } //! [23] //! [24] QVector a, b; a.resize(100000); // make a big vector filled with 0. QVector::iterator i = a.begin(); // WRONG way of using the iterator i: b = a; /* Now we should be careful with iterator i since it will point to shared data If we do *i = 4 then we would change the shared instance (both vectors) The behavior differs from STL containers. Avoid doing such things in Qt. */ a[0] = 5; /* Container a is now detached from the shared data, and even though i was an iterator from the container a, it now works as an iterator in b. Here the situation is that (*i) == 0. */ b.clear(); // Now the iterator i is completely invalid. int j = *i; // Undefined behavior! /* The data from b (which i pointed to) is gone. This would be well-defined with STL containers (and (*i) == 5), but with QVector this is likely to crash. */ //! [24]