QStringList Class

Member Function Documentation

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

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

See also lastIndexOf().

Returns the index position of the last match of str 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.

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

See also indexOf().

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 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=().

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

This is an overloaded function.

Move-constructs from QList<QString>.

After a successful construction, other will be empty.

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

Returns true if the list contains the string str; otherwise returns false.

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

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

[noexcept] bool QStringList::contains(QLatin1StringView str, Qt::CaseSensitivity cs = Qt::CaseSensitive) const

This is an overloaded function.

Returns true if the list contains the Latin-1 string viewed by str; otherwise returns false.

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

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

[noexcept] bool QStringList::contains(QStringView str, Qt::CaseSensitivity cs = Qt::CaseSensitive) const

This is an overloaded function.

Returns true if the list contains the string str; otherwise returns false.

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

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;
    for (const auto &str : std::as_const(list)) {
        if (str.contains("Bill"))
            result += str;
    }

See also contains().

[since 6.7] QStringList QStringList::filter(const QStringMatcher &matcher) const

This is an overloaded function.

Returns a list of all the strings matched by matcher (i.e. for which matcher.indexIn() returns an index >= 0).

Using a QStringMatcher may be faster when searching in large lists and/or in lists with long strings (the best way to find out is benchmarking).

For example:

    QStringList veryLongList;
    QStringMatcher matcher(u"Straße", Qt::CaseInsensitive);
    QStringList filtered = veryLongList.filter(matcher);

This function was introduced in Qt 6.7.

See also contains().

[since 6.7] QStringList QStringList::filter(QLatin1StringView str, Qt::CaseSensitivity cs = Qt::CaseSensitive) const

This is an overloaded function.

This function was introduced in Qt 6.7.

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

This is an overloaded function.

QStringList QStringList::filter(const QRegularExpression &re) const

This is an overloaded function.

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

qsizetype QStringList::indexOf(const QRegularExpression &re, qsizetype from = 0) const

This is an overloaded function.

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

See also lastIndexOf().

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().

QString QStringList::join(QStringView separator) const

This is an overloaded function.

QString QStringList::join(QLatin1StringView separator) const

This function overloads join().

QString QStringList::join(QChar separator) const

This function overloads join().

qsizetype QStringList::lastIndexOf(const QRegularExpression &re, qsizetype from = -1) const

This is an overloaded function.

Returns the index position of the last exact match of re 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.

See also indexOf().

qsizetype 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.

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.

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

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(QStringView before, QStringView after, Qt::CaseSensitivity cs = Qt::CaseSensitive)

This is an overloaded function.

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

This is an overloaded function.

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

This is an overloaded function.

QStringList &QStringList::replaceInStrings(const QRegularExpression &re, const QString &after)

This is an overloaded function.

Replaces every occurrence of the regular expression re, 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(QRegularExpression("^a"), "o");
    // list == ["olpha", "beta", "gamma", "epsilon"]

For regular expressions that contain capturing groups, occurrences of \1, \2, ..., in after are replaced with the string captured by the corresponding capturing group.

For example:

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

void QStringList::sort(Qt::CaseSensitivity cs = Qt::CaseSensitive)

Sorts the list of strings in ascending order.

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

Sorting is performed using the STL's std::sort() algorithm, which averages 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.

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.

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

This is an overloaded function.

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

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

Copy assignment operator from QList<QString>. Assigns the other list of strings to this string list.

After the operation, other and *this will be equal.

QStringList &QStringList::operator=(QList<QString> &&other)

This is an overloaded function.

Move assignment operator from QList<QString>. Moves the other list of strings to this string list.

After the operation, other will be empty.