QStringList Class Reference

Member Function Documentation

QStringList::QStringList ()

Constructs an empty string list.

QStringList::QStringList ( const QString & str )

Constructs a string list that contains the given string, str. Longer lists are easily created like this:

     QStringList longerList = (QStringList() << str1 << str2 << str3);

See also append().

QStringList::QStringList ( const QStringList & other )

Constructs a copy of the other string list.

This operation takes constant time because QStringList is implicitly shared, making the process of returning a QStringList from a function very fast. If a shared instance is modified, it will be copied (copy-on-write), and that takes linear time.

See also operator=().

QStringList::QStringList ( const QList<QString> & other )

Constructs a copy of other.

This operation takes constant time, because QStringList is implicitly shared. This makes returning a QStringList from a function very fast. If a shared instance is modified, it will be copied (copy-on-write), and that takes linear time.

See also operator=().

bool QStringList::contains ( const QString & str, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const

Returns true if the list contains the string str; otherwise returns false. The search is case insensitive if cs is Qt::CaseInsensitive; the search is case sensitive by default.

See also indexOf(), lastIndexOf(), and QString::contains().

QStringList QStringList::filter ( const QString & str, Qt::CaseSensitivity cs = Qt::CaseSensitive ) const

Returns a list of all the strings containing the substring str.

If cs is Qt::CaseSensitive (the default), the string comparison is case sensitive; otherwise the comparison is case insensitive.

     QStringList list;
     list << "Bill Murray" << "John Doe" << "Bill Clinton";

     QStringList result;
     result = list.filter("Bill");
     // result: ["Bill Murray", "Bill Clinton"]

This is equivalent to

     QStringList result;
     foreach (const QString &str, list) {
         if (str.contains("Bill"))
             result += str;
     }

See also contains().

QStringList QStringList::filter ( const QRegExp & rx ) const

This is an overloaded function.

Returns a list of all the strings that match the regular expression rx.

int QStringList::indexOf ( const QRegExp & rx, int from = 0 ) const

Returns the index position of the first exact match of rx in the list, searching forward from index position from. Returns -1 if no item matched.

By default, this function is case sensitive.

See also lastIndexOf(), contains(), and QRegExp::exactMatch().

int QStringList::indexOf ( const QString & value, int from = 0 ) const

Returns the index position of the first occurrence of value in the list, searching forward from index position from. Returns -1 if no item matched.

See also lastIndexOf(), contains(), and QList::indexOf().

int QStringList::indexOf ( QRegExp & rx, int from = 0 ) const

This function overloads indexOf().

Returns the index position of the first exact match of rx in the list, searching forward from index position from. Returns -1 if no item matched.

By default, this function is case sensitive.

If an item matched, the rx regular expression will contain the matched objects (see QRegExp::matchedLength, QRegExp::cap).

This function was introduced in Qt 4.5.

See also lastIndexOf(), contains(), and QRegExp::exactMatch().

QString QStringList::join ( const QString & separator ) const

Joins all the string list's strings into a single string with each element separated by the given separator (which can be an empty string).

See also QString::split().

int QStringList::lastIndexOf ( const QRegExp & rx, int from = -1 ) const

Returns the index position of the last exact match of rx in the list, searching backward from index position from. If from is -1 (the default), the search starts at the last item. Returns -1 if no item matched.

By default, this function is case sensitive.

See also indexOf(), contains(), and QRegExp::exactMatch().

int QStringList::lastIndexOf ( const QString & value, int from = -1 ) const

Returns the index position of the last occurrence of value in the list, searching backward from index position from. If from is -1 (the default), the search starts at the last item. Returns -1 if no item matched.

By default, this function is case sensitive.

See also indexOf() and QList::lastIndexOf().

int QStringList::lastIndexOf ( QRegExp & rx, int from = -1 ) const

This function overloads lastIndexOf().

Returns the index position of the last exact match of rx in the list, searching backward from index position from. If from is -1 (the default), the search starts at the last item. Returns -1 if no item matched.

By default, this function is case sensitive.

If an item matched, the rx regular expression will contain the matched objects (see QRegExp::matchedLength, QRegExp::cap).

This function was introduced in Qt 4.5.

See also indexOf(), contains(), and QRegExp::exactMatch().

int QStringList::removeDuplicates ()

This function removes duplicate entries from a list. The entries do not have to be sorted. They will retain their original order.

Returns the number of removed entries.

This function was introduced in Qt 4.5.

QStringList & QStringList::replaceInStrings ( const QString & before, const QString & after, Qt::CaseSensitivity cs = Qt::CaseSensitive )

Returns a string list where every string has had the before text replaced with the after text wherever the before text is found. The before text is matched case-sensitively or not depending on the cs flag.

For example:

     QStringList list;
     list << "alpha" << "beta" << "gamma" << "epsilon";
     list.replaceInStrings("a", "o");
     // list == ["olpho", "beto", "gommo", "epsilon"]

See also QString::replace().

QStringList & QStringList::replaceInStrings ( const QRegExp & rx, const QString & after )

This is an overloaded function.

Replaces every occurrence of the regexp rx, in each of the string lists's strings, with after. Returns a reference to the string list.

For example:

     QStringList list;
     list << "alpha" << "beta" << "gamma" << "epsilon";
     list.replaceInStrings(QRegExp("^a"), "o");
     // list == ["olpha", "beta", "gamma", "epsilon"]

For regular expressions that contain capturing parentheses, occurrences of \1, \2, ..., in after are replaced with rx.cap(1), rx.cap(2), ...

For example:

     QStringList list;
     list << "Bill Clinton" << "Murray, Bill";
     list.replaceInStrings(QRegExp("^(.*), (.*)$"), "\\2 \\1");
     // list == ["Bill Clinton", "Bill Murray"]

void QStringList::sort ()

Sorts the list of strings in ascending order (case sensitively).

Sorting is performed using Qt's qSort() algorithm, which operates in linear-logarithmic time, i.e. O(n log n).

If you want to sort your strings in an arbitrary order, consider using the QMap class. For example, you could use a QMap<QString, QString> to create a case-insensitive ordering (e.g. with the keys being lower-case versions of the strings, and the values being the strings), or a QMap<int, QString> to sort the strings by some integer index.

See also qSort().

QStringList QStringList::operator+ ( const QStringList & other ) const

Returns a string list that is the concatenation of this string list with the other string list.

See also append().

QStringList & QStringList::operator<< ( const QString & str )

Appends the given string, str, to this string list and returns a reference to the string list.

See also append().

QStringList & QStringList::operator<< ( const QStringList & other )

This is an overloaded function.

Appends the other string list to the string list and returns a reference to the latter string list.