diff options
Diffstat (limited to 'doc/codesnippets/doc/src/snippets/code/src_corelib_tools_qhash.cpp')
-rw-r--r-- | doc/codesnippets/doc/src/snippets/code/src_corelib_tools_qhash.cpp | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/doc/codesnippets/doc/src/snippets/code/src_corelib_tools_qhash.cpp b/doc/codesnippets/doc/src/snippets/code/src_corelib_tools_qhash.cpp new file mode 100644 index 000000000..05f6eb306 --- /dev/null +++ b/doc/codesnippets/doc/src/snippets/code/src_corelib_tools_qhash.cpp @@ -0,0 +1,259 @@ +//! [0] +QHash<QString, int> hash; +//! [0] + + +//! [1] +hash["one"] = 1; +hash["three"] = 3; +hash["seven"] = 7; +//! [1] + + +//! [2] +hash.insert("twelve", 12); +//! [2] + + +//! [3] +int num1 = hash["thirteen"]; +int num2 = hash.value("thirteen"); +//! [3] + + +//! [4] +int timeout = 30; +if (hash.contains("TIMEOUT")) + timeout = hash.value("TIMEOUT"); +//! [4] + + +//! [5] +int timeout = hash.value("TIMEOUT", 30); +//! [5] + + +//! [6] +// WRONG +QHash<int, QWidget *> hash; +... +for (int i = 0; i < 1000; ++i) { + if (hash[i] == okButton) + cout << "Found button at index " << i << endl; +} +//! [6] + + +//! [7] +QHashIterator<QString, int> i(hash); +while (i.hasNext()) { + i.next(); + cout << i.key() << ": " << i.value() << endl; +} +//! [7] + + +//! [8] +QHash<QString, int>::const_iterator i = hash.constBegin(); +while (i != hash.constEnd()) { + cout << i.key() << ": " << i.value() << endl; + ++i; +} +//! [8] + + +//! [9] +hash.insert("plenty", 100); +hash.insert("plenty", 2000); +// hash.value("plenty") == 2000 +//! [9] + + +//! [10] +QList<int> values = hash.values("plenty"); +for (int i = 0; i < values.size(); ++i) + cout << values.at(i) << endl; +//! [10] + + +//! [11] +QHash<QString, int>::iterator i = hash.find("plenty"); +while (i != hash.end() && i.key() == "plenty") { + cout << i.value() << endl; + ++i; +} +//! [11] + + +//! [12] +QHash<QString, int> hash; +... +foreach (int value, hash) + cout << value << endl; +//! [12] + + +//! [13] +#ifndef EMPLOYEE_H +#define EMPLOYEE_H + +class Employee +{ +public: + Employee() {} + Employee(const QString &name, const QDate &dateOfBirth); + ... + +private: + QString myName; + QDate myDateOfBirth; +}; + +inline bool operator==(const Employee &e1, const Employee &e2) +{ + return e1.name() == e2.name() + && e1.dateOfBirth() == e2.dateOfBirth(); +} + +inline uint qHash(const Employee &key) +{ + return qHash(key.name()) ^ key.dateOfBirth().day(); +} + +#endif // EMPLOYEE_H +//! [13] + + +//! [14] +QHash<QString, int> hash; +hash.reserve(20000); +for (int i = 0; i < 20000; ++i) + hash.insert(keys[i], values[i]); +//! [14] + + +//! [15] +QHash<QObject *, int> objectHash; +... +QHash<QObject *, int>::iterator i = objectHash.find(obj); +while (i != objectHash.end() && i.key() == obj) { + if (i.value() == 0) { + i = objectHash.erase(i); + } else { + ++i; + } +} +//! [15] + + +//! [16] +QHash<QString, int> hash; +... +QHash<QString, int>::const_iterator i = hash.find("HDR"); +while (i != hash.end() && i.key() == "HDR") { + cout << i.value() << endl; + ++i; +} +//! [16] + + +//! [17] +QHash<QString, int> hash; +hash.insert("January", 1); +hash.insert("February", 2); +... +hash.insert("December", 12); + +QHash<QString, int>::iterator i; +for (i = hash.begin(); i != hash.end(); ++i) + cout << i.key() << ": " << i.value() << endl; +//! [17] + + +//! [18] +QHash<QString, int>::iterator i; +for (i = hash.begin(); i != hash.end(); ++i) + i.value() += 2; +//! [18] + + +//! [19] +QHash<QString, int>::iterator i = hash.begin(); +while (i != hash.end()) { + if (i.key().startsWith("_")) + i = hash.erase(i); + else + ++i; +} +//! [19] + + +//! [20] +QHash<QString, int>::iterator i = hash.begin(); +while (i != hash.end()) { + QHash<QString, int>::iterator prev = i; + ++i; + if (prev.key().startsWith("_")) + hash.erase(prev); +} +//! [20] + + +//! [21] +// WRONG +while (i != hash.end()) { + if (i.key().startsWith("_")) + hash.erase(i); + ++i; +} +//! [21] + + +//! [22] +if (i.key() == "Hello") + i.value() = "Bonjour"; +//! [22] + + +//! [23] +QHash<QString, int> hash; +hash.insert("January", 1); +hash.insert("February", 2); +... +hash.insert("December", 12); + +QHash<QString, int>::const_iterator i; +for (i = hash.constBegin(); i != hash.constEnd(); ++i) + cout << i.key() << ": " << i.value() << endl; +//! [23] + + +//! [24] +QMultiHash<QString, int> hash1, hash2, hash3; + +hash1.insert("plenty", 100); +hash1.insert("plenty", 2000); +// hash1.size() == 2 + +hash2.insert("plenty", 5000); +// hash2.size() == 1 + +hash3 = hash1 + hash2; +// hash3.size() == 3 +//! [24] + + +//! [25] +QList<int> values = hash.values("plenty"); +for (int i = 0; i < values.size(); ++i) + cout << values.at(i) << endl; +//! [25] + + +//! [26] +QMultiHash<QString, int>::iterator i = hash.find("plenty"); +while (i != hash.end() && i.key() == "plenty") { + cout << i.value() << endl; + ++i; +} +//! [26] |