QStringList Class

Member Function Documentation

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.

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().

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. The search is case insensitive if cs is Qt::CaseInsensitive; the search is case sensitive by default.

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

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. The search is case insensitive if cs is Qt::CaseInsensitive; the search is case sensitive by default.

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().

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. 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(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.