QStringView Class

     void myfun1(QStringView sv);        // preferred
     void myfun2(const QStringView &sv); // compiles and works, but slower

Member Function Documentation

Splits the view into substring views wherever sep occurs, and returns the list of those string views.

See QString::split() for how sep, behavior and cs interact to form the result.

This function was introduced in Qt 6.0.

template <typename... Args> QString QStringView::arg(Args &&... args) const

Replaces occurrences of %N in this string with the corresponding argument from args. The arguments are not positional: the first of the args replaces the %N with the lowest N (all of them), the second of the args the %N with the next-lowest N etc.

Args can consist of anything that implicitly converts to QString, QStringView or QLatin1StringView.

In addition, the following types are also supported: QChar, QLatin1Char.

See also QString::arg().

Compares this string view to the Latin-1 string view l1, or the character ch. Returns a negative integer if this string view is less than l1 or ch, a positive integer if it is greater than l1 or ch, and zero if they are equal.

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

See also operator==(), operator<(), and operator>().

Returns true if this string view starts with the UTF-16 string viewed by str, the Latin-1 string viewed by l1, or the character ch respectively; otherwise returns false.

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

See also endsWith().

Returns true if this string view ends with the UTF-16 string viewed by str, the Latin-1 string viewed by l1, or the character ch respectively; otherwise returns false.

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

See also startsWith().

Returns the index position of the first occurrence of the UTF-16 string viewed by str, the Latin-1 string viewed by l1, or the character ch respectively, in this string view, searching forward from index position from. Returns -1 if str, l1 or ch is not found, respectively.

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

If from is -1, the search starts at the last character; if it is -2, at the next to last character and so on.

See also QString::indexOf().

Returns true if this string view contains an occurrence of the UTF-16 string viewed by str, the Latin-1 string viewed by l1, or the character ch respectively; otherwise returns false.

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

See also indexOf().

Returns the index position of the last occurrence of the UTF-16 string viewed by str, the Latin-1 string viewed by l1, or the character ch respectively, in this string view, searching backward from index position from.

If from is -1, the search starts at the last character; if it is -2, at the next to last character and so on.

Returns -1 if str, l1 or c is not found, respectively.

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

See also QString::lastIndexOf().

This function overloads lastIndexOf().

Returns the index position of the last occurrence of the UTF-16 string viewed by str or the Latin-1 string viewed by l1 respectively, in this string view searching backward from the last character of this string view. Returns -1 if str or l1 is not found, respectively.

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

This function was introduced in Qt 6.2.

See also QString::lastIndexOf().

[constexpr noexcept(...), since 6.0] template <typename Needle, typename... Flags> decltype(qTokenize(*this, std::forward<Needle>(needle), flags...)) QStringView::tokenize(Needle &&sep, Flags... flags) const

Splits the string into substring views wherever sep occurs, and returns a lazy sequence of those strings.

Equivalent to

 return QStringTokenizer{std::forward<Needle>(sep), flags...};

except it works without C++17 Class Template Argument Deduction (CTAD) enabled in the compiler.

See QStringTokenizer for how sep and flags interact to form the result.

 QStringTokenizer result = sv.tokenize(sep);

(without template arguments). If you can't use C++17 CTAD, you must store the return value only in auto variables:

 auto result = sv.tokenize(sep);

This is because the template arguments of QStringTokenizer have a very subtle dependency on the specific tokenize() overload from which they are returned, and they don't usually correspond to the type used for the separator.

This function was introduced in Qt 6.0.

See also QStringTokenizer and qTokenize().

[constexpr noexcept] QStringView::QStringView()

Constructs a null string view.

See also isNull().

[constexpr noexcept] QStringView::QStringView(std::nullptr_t)

Constructs a null string view.

See also isNull().

[constexpr] template <typename Char, QStringView::if_compatible_char<Char> = true> QStringView::QStringView(const Char *str, qsizetype len)

Constructs a string view on str with length len.

The range [str,len) must remain valid for the lifetime of this string view object.

Passing nullptr as str is safe if len is 0, too, and results in a null string view.

The behavior is undefined if len is negative or, when positive, if str is nullptr.

This constructor only participates in overload resolution if Char is a compatible character type. The compatible character types are: QChar, ushort, char16_t and (on platforms, such as Windows, where it is a 16-bit type) wchar_t.

[constexpr] template <typename Char, QStringView::if_compatible_char<Char> = true> QStringView::QStringView(const Char *first, const Char *last)

Constructs a string view on first with length (last - first).

The range [first,last) must remain valid for the lifetime of this string view object.

Passing \nullptr as first is safe if last is nullptr, too, and results in a null string view.

The behavior is undefined if last precedes first, or first is nullptr and last is not.

This constructor only participates in overload resolution if Char is a compatible character type. The compatible character types are: QChar, ushort, char16_t and (on platforms, such as Windows, where it is a 16-bit type) wchar_t.

[constexpr noexcept] template <typename Char, size_t N> QStringView::QStringView(const Char (&)[N] string)

Constructs a string view on the character string literal string. The view covers the array until the first Char(0) is encountered, or N, whichever comes first. If you need the full array, use fromArray() instead.

string must remain valid for the lifetime of this string view object.

This constructor only participates in overload resolution if string is an actual array and Char is a compatible character type. The compatible character types are: QChar, ushort, char16_t and (on platforms, such as Windows, where it is a 16-bit type) wchar_t.

See also fromArray.

[constexpr noexcept] template <typename Char> QStringView::QStringView(const Char *str)

Constructs a string view on str. The length is determined by scanning for the first Char(0).

str must remain valid for the lifetime of this string view object.

Passing nullptr as str is safe and results in a null string view.

This constructor only participates in overload resolution if str is not an array and if Char is a compatible character type. The compatible character types are: QChar, ushort, char16_t and (on platforms, such as Windows, where it is a 16-bit type) wchar_t.

[noexcept] QStringView::QStringView(const QString &str)

Constructs a string view on str.

str.data() must remain valid for the lifetime of this string view object.

The string view will be null if and only if str.isNull().

[constexpr noexcept] template <typename Container, QStringView::if_compatible_container<Container> = true> QStringView::QStringView(const Container &str)

Constructs a string view on str. The length is taken from std::size(str).

std::data(str) must remain valid for the lifetime of this string view object.

This constructor only participates in overload resolution if Container is a container with a compatible character type as value_type. The compatible character types are: QChar, ushort, char16_t and (on platforms, such as Windows, where it is a 16-bit type) wchar_t.

The string view will be empty if and only if std::size(str) == 0. It is unspecified whether this constructor can result in a null string view (std::data(str) would have to return nullptr for this).

See also isNull() and isEmpty().

[constexpr noexcept] QChar QStringView::at(qsizetype n) const

Returns the character at position n in this string view.

The behavior is undefined if n is negative or not less than size().

See also operator[](), front(), and back().

[constexpr] QChar QStringView::back() const

Returns the last character in the string view. Same as last().

This function is provided for STL compatibility.

See also front(), first(), and last().

[noexcept] QStringView::const_iterator QStringView::begin() const

Returns a const STL-style iterator pointing to the first character in the string view.

This function is provided for STL compatibility.

See also end(), constBegin(), cbegin(), rbegin(), and data().

[noexcept] QStringView::const_iterator QStringView::cbegin() const

Same as begin().

This function is provided for STL compatibility.

See also cend(), begin(), constBegin(), crbegin(), and data().

[noexcept] QStringView::const_iterator QStringView::cend() const

Same as end().

This function is provided for STL compatibility.

See also cbegin(), end(), constEnd(), and crend().

[constexpr noexcept] void QStringView::chop(qsizetype length)

Truncates this string view by length characters.

Same as *this = left(size() - length).

See also mid(), left(), right(), chopped(), and truncate().

[constexpr noexcept] QStringView QStringView::chopped(qsizetype length) const

Returns the substring of length size() - length starting at the beginning of this object.

Same as left(size() - length).

See also mid(), left(), right(), chop(), and truncate().

[noexcept] int QStringView::compare(QStringView str, Qt::CaseSensitivity cs = Qt::CaseSensitive) const

Compares this string view with string view str and returns a negative integer if this string view is less than str, a positive integer if it is greater than str, and zero if they are equal.

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

See also operator==(), operator<(), and operator>().

[noexcept, since 6.5] int QStringView::compare(QUtf8StringView str, Qt::CaseSensitivity cs = Qt::CaseSensitive) const

Compares this string view with QUtf8StringView str and returns a negative integer if this string view is less than str, a positive integer if it is greater than str, and zero if they are equal.

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

This function was introduced in Qt 6.5.

See also operator==(), operator<(), and operator>().

[noexcept, since 6.1] QStringView::const_iterator QStringView::constBegin() const

Same as begin().

This function was introduced in Qt 6.1.

See also constEnd(), begin(), cbegin(), crbegin(), and data().

[noexcept, since 6.0] QStringView::const_pointer QStringView::constData() const

Returns a const pointer to the first character in the string view.

This function was introduced in Qt 6.0.

See also data(), begin(), end(), and utf16().

[noexcept, since 6.1] QStringView::const_iterator QStringView::constEnd() const

Same as end().

This function was introduced in Qt 6.1.

See also constBegin(), end(), cend(), and crend().

[since 6.1] bool QStringView::contains(const QRegularExpression &re, QRegularExpressionMatch *rmatch = nullptr) const

Returns true if the regular expression re matches somewhere in this string view; otherwise returns false.

If the match is successful and rmatch is not nullptr, it also writes the results of the match into the QRegularExpressionMatch object pointed to by rmatch.

This function was introduced in Qt 6.1.

See also QRegularExpression::match().

[since 6.1] qsizetype QStringView::count(const QRegularExpression &re) const

Returns the number of times the regular expression re matches in the string view.

For historical reasons, this function counts overlapping matches. This behavior is different from simply iterating over the matches in the string view using QRegularExpressionMatchIterator.

This function was introduced in Qt 6.1.

See also QRegularExpression::globalMatch().

[noexcept, since 6.0] qsizetype QStringView::count(QChar ch, Qt::CaseSensitivity cs = Qt::CaseSensitive) const

This function overloads count().

Returns the number of occurrences of the character ch in the string view.

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

This function was introduced in Qt 6.0.

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

[noexcept, since 6.0] qsizetype QStringView::count(QStringView str, Qt::CaseSensitivity cs = Qt::CaseSensitive) const

This function overloads count().

Returns the number of (potentially overlapping) occurrences of the string view str in this string view.

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

This function was introduced in Qt 6.0.

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

[since 6.4] qsizetype QStringView::count(QLatin1StringView l1, Qt::CaseSensitivity cs = Qt::CaseSensitive) const

This function overloads count().

Returns the number of (potentially overlapping) occurrences of the Latin-1 string viewed by l1 in this string view.

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

This function was introduced in Qt 6.4.

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

[noexcept] QStringView::const_reverse_iterator QStringView::crbegin() const

Same as rbegin().

This function is provided for STL compatibility.

See also crend(), rbegin(), and cbegin().

[noexcept] QStringView::const_reverse_iterator QStringView::crend() const

Same as rend().

This function is provided for STL compatibility.

See also crbegin(), rend(), and cend().

[noexcept] QStringView::const_pointer QStringView::data() const

Returns a const pointer to the first character in the string view.

See also begin(), end(), and utf16().

[constexpr noexcept] bool QStringView::empty() const

Returns whether this string view is empty - that is, whether size() == 0.

This function is provided for STL compatibility.

See also isEmpty(), isNull(), size(), and length().

[noexcept] QStringView::const_iterator QStringView::end() const

Returns a const STL-style iterator pointing to the imaginary character after the last character in the list.

This function is provided for STL compatibility.

See also begin(), constEnd(), cend(), and rend().

[constexpr noexcept, since 6.0] QStringView QStringView::first(qsizetype n) const

Returns a string view that points to the first n characters of this string view.

This function was introduced in Qt 6.0.

See also last(), sliced(), startsWith(), chopped(), chop(), and truncate().

[constexpr] QChar QStringView::first() const

Returns the first character in the string view. Same as front().

This function is provided for compatibility with other Qt containers.

See also front(), back(), and last().

[static constexpr noexcept] template <typename Char, size_t Size, QStringView::if_compatible_char<Char> = true> QStringView QStringView::fromArray(const Char (&)[Size] string)

Constructs a string view on the full character string literal string, including any trailing Char(0). If you don't want the null-terminator included in the view then you can chop() it off when you are certain it is at the end. Alternatively you can use the constructor overload taking an array literal which will create a view up to, but not including, the first null-terminator in the data.

string must remain valid for the lifetime of this string view object.

This function will work with any array literal if Char is a compatible character type. The compatible character types are: QChar, ushort, char16_t and (on platforms, such as Windows, where it is a 16-bit type) wchar_t.

[constexpr] QChar QStringView::front() const

Returns the first character in the string view. Same as first().

This function is provided for STL compatibility.

See also back(), first(), and last().

[since 6.1] qsizetype QStringView::indexOf(const QRegularExpression &re, qsizetype from = 0, QRegularExpressionMatch *rmatch = nullptr) const

Returns the index position of the first match of the regular expression re in the string view, searching forward from index position from. Returns -1 if re didn't match anywhere.

If the match is successful and rmatch is not nullptr, it also writes the results of the match into the QRegularExpressionMatch object pointed to by rmatch.

This function was introduced in Qt 6.1.

[constexpr noexcept] bool QStringView::isEmpty() const

Returns whether this string view is empty - that is, whether size() == 0.

This function is provided for compatibility with other Qt containers.

See also empty(), isNull(), size(), and length().

[noexcept, since 6.7] bool QStringView::isLower() const

Returns true if this view is identical to its lowercase folding.

Note that this does not mean that the string view does not contain uppercase letters (some uppercase letters do not have a lowercase folding; they are left unchanged by toString().toLower()). For more information, refer to the Unicode standard, section 3.13.

This function was introduced in Qt 6.7.

See also QChar::toLower() and isUpper().

[constexpr noexcept] bool QStringView::isNull() const

Returns whether this string view is null - that is, whether data() == nullptr.

This functions is provided for compatibility with other Qt containers.

See also empty(), isEmpty(), size(), and length().

[noexcept] bool QStringView::isRightToLeft() const

Returns true if the string view is read right to left.

See also QString::isRightToLeft().

[noexcept, since 6.7] bool QStringView::isUpper() const

Returns true if this view is identical to its uppercase folding.

Note that this does not mean that the the string view does not contain lowercase letters (some lowercase letters do not have a uppercase folding; they are left unchanged by toString().toUpper()). For more information, refer to the Unicode standard, section 3.13.

This function was introduced in Qt 6.7.

See also QChar::toUpper() and isLower().

[noexcept] bool QStringView::isValidUtf16() const

Returns true if the string view contains valid UTF-16 encoded data, or false otherwise.

Note that this function does not perform any special validation of the data; it merely checks if it can be successfully decoded from UTF-16. The data is assumed to be in host byte order; the presence of a BOM is meaningless.

See also QString::isValidUtf16().

[constexpr noexcept, since 6.0] QStringView QStringView::last(qsizetype n) const

Returns a string view that points to the last n characters of this string view.

This function was introduced in Qt 6.0.

See also first(), sliced(), endsWith(), chopped(), chop(), and truncate().

[constexpr] QChar QStringView::last() const

Returns the last character in the string view. Same as back().

This function is provided for compatibility with other Qt containers.

See also back(), front(), and first().

[noexcept, since 6.3] qsizetype QStringView::lastIndexOf(QChar c, Qt::CaseSensitivity cs = Qt::CaseSensitive) const

This function overloads lastIndexOf().

This function was introduced in Qt 6.3.

[since 6.2] qsizetype QStringView::lastIndexOf(const QRegularExpression &re, QRegularExpressionMatch *rmatch = nullptr) const

Returns the index position of the last match of the regular expression re in the string view. Returns -1 if re didn't match anywhere.

If the match is successful and rmatch is not nullptr, it also writes the results of the match into the QRegularExpressionMatch object pointed to by rmatch.

This function was introduced in Qt 6.2.

[since 6.1] qsizetype QStringView::lastIndexOf(const QRegularExpression &re, qsizetype from, QRegularExpressionMatch *rmatch = nullptr) const

Returns the index position of the last match of the regular expression re in the string view, which starts before the index position from.

If from is -1, the search starts at the last character; if it is -2, at the next to last character and so on.

Returns -1 if re didn't match anywhere.

If the match is successful and rmatch is not nullptr, it also writes the results of the match into the QRegularExpressionMatch object pointed to by rmatch.

This function was introduced in Qt 6.1.

[constexpr noexcept] qsizetype QStringView::length() const

Same as size().

This function is provided for compatibility with other Qt containers.

See also empty(), isEmpty(), isNull(), and size().

[since 6.4] int QStringView::localeAwareCompare(QStringView other) const

Compares this string view with the other string view and returns an integer less than, equal to, or greater than zero if this string view is less than, equal to, or greater than the other string view.

The comparison is performed in a locale- and also platform-dependent manner. Use this function to present sorted lists of strings to the user.

This function was introduced in Qt 6.4.

See also Comparing Strings.

[noexcept] QStringView::const_reverse_iterator QStringView::rbegin() const

Returns a const STL-style reverse iterator pointing to the first character in the string view, in reverse order.

This function is provided for STL compatibility.

See also rend(), crbegin(), and begin().

[noexcept] QStringView::const_reverse_iterator QStringView::rend() const

Returns a STL-style reverse iterator pointing to one past the last character in the string view, in reverse order.

This function is provided for STL compatibility.

See also rbegin(), crend(), and end().

[constexpr noexcept] qsizetype QStringView::size() const

Returns the size of this string view, in UTF-16 code units (that is, surrogate pairs count as two for the purposes of this function, the same as in QString).

See also empty(), isEmpty(), isNull(), and length().

[constexpr noexcept, since 6.0] QStringView QStringView::sliced(qsizetype pos, qsizetype n) const

Returns a string view that points to n characters of this string view, starting at position pos.

This function was introduced in Qt 6.0.

See also first(), last(), chopped(), chop(), and truncate().

[constexpr noexcept, since 6.0] QStringView QStringView::sliced(qsizetype pos) const

This is an overloaded function.

Returns a string view starting at position pos in this object, and extending to its end.

This function was introduced in Qt 6.0.

See also first(), last(), chopped(), chop(), and truncate().

[since 6.0] QList<QStringView> QStringView::split(const QRegularExpression &re, Qt::SplitBehavior behavior = Qt::KeepEmptyParts) const

Splits the string into substring views wherever the regular expression re matches, and returns the list of those strings. If re does not match anywhere in the string, split() returns a single-element list containing this string as view.

This function was introduced in Qt 6.0.

[since 6.0] CFStringRef QStringView::toCFString() const

Creates a CFString from this QStringView.

The caller owns the CFString and is responsible for releasing it.

This function was introduced in Qt 6.0.

[since 6.0] double QStringView::toDouble(bool *ok = nullptr) const

Returns the string view converted to a double value.

Returns an infinity if the conversion overflows or 0.0 if the conversion fails for other reasons (e.g. underflow).

If ok is not nullptr, failure is reported by setting *ok to false, and success by setting *ok to true.

The string conversion will always happen in the 'C' locale. For locale dependent conversion use QLocale::toDouble()

For historic reasons, this function does not handle thousands group separators. If you need to convert such numbers, use QLocale::toDouble().

This function was introduced in Qt 6.0.

See also QString::toDouble().

[since 6.0] float QStringView::toFloat(bool *ok = nullptr) const

Returns the string view converted to a float value.

Returns an infinity if the conversion overflows or 0.0 if the conversion fails for other reasons (e.g. underflow).

If ok is not nullptr, failure is reported by setting *ok to false, and success by setting *ok to true.

The string conversion will always happen in the 'C' locale. For locale dependent conversion use QLocale::toFloat()

This function was introduced in Qt 6.0.

See also QString::toFloat().

[since 6.0] int QStringView::toInt(bool *ok = nullptr, int base = 10) const

Returns the string view converted to an int using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If ok is not nullptr, failure is reported by setting *ok to false, and success by setting *ok to true.

If base is 0, the C language convention is used: if the string view begins with "0x", base 16 is used; otherwise, if the string view begins with "0", base 8 is used; otherwise, base 10 is used.

The string conversion will always happen in the 'C' locale. For locale dependent conversion use QLocale::toInt()

This function was introduced in Qt 6.0.

See also QString::toInt().

QByteArray QStringView::toLatin1() const

Returns a Latin-1 representation of the string as a QByteArray.

The behavior is undefined if the string contains non-Latin1 characters.

See also toUtf8(), toLocal8Bit(), and QStringEncoder.

QByteArray QStringView::toLocal8Bit() const

Returns a local 8-bit representation of the string as a QByteArray.

On Unix systems this is equivalen to toUtf8(), on Windows the systems current code page is being used.

The behavior is undefined if the string contains characters not supported by the locale's 8-bit encoding.

See also toLatin1(), toUtf8(), and QStringEncoder.

[since 6.0] long QStringView::toLong(bool *ok = nullptr, int base = 10) const

Returns the string view converted to a long using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If ok is not nullptr, failure is reported by setting *ok to false, and success by setting *ok to true.

If base is 0, the C language convention is used: if the string view begins with "0x", base 16 is used; otherwise, if the string view begins with "0", base 8 is used; otherwise, base 10 is used.

The string conversion will always happen in the 'C' locale. For locale dependent conversion use QLocale::toLong()

This function was introduced in Qt 6.0.

See also QString::toLong().

[since 6.0] qlonglong QStringView::toLongLong(bool *ok = nullptr, int base = 10) const

Returns the string view converted to a long long using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If ok is not nullptr, failure is reported by setting *ok to false, and success by setting *ok to true.

If base is 0, the C language convention is used: if the string view begins with "0x", base 16 is used; otherwise, if the string view begins with "0", base 8 is used; otherwise, base 10 is used.

The string conversion will always happen in the 'C' locale. For locale dependent conversion use QLocale::toLongLong()

This function was introduced in Qt 6.0.

See also QString::toLongLong().

[since 6.0] NSString *QStringView::toNSString() const

Creates an NSString from this QStringView.

The NSString is autoreleased.

This function was introduced in Qt 6.0.

[since 6.0] short QStringView::toShort(bool *ok = nullptr, int base = 10) const

Returns the string view converted to a short using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If ok is not nullptr, failure is reported by setting *ok to false, and success by setting *ok to true.

If base is 0, the C language convention is used: if the string view begins with "0x", base 16 is used; otherwise, if the string view begins with "0", base 8 is used; otherwise, base 10 is used.

The string conversion will always happen in the 'C' locale. For locale dependent conversion use QLocale::toShort()

This function was introduced in Qt 6.0.

See also QString::toShort().

QString QStringView::toString() const

Returns a deep copy of this string view's data as a QString.

The return value will be the null QString if and only if this string view is null.

[since 6.0] uint QStringView::toUInt(bool *ok = nullptr, int base = 10) const

Returns the string view converted to an unsigned int using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If ok is not nullptr, failure is reported by setting *ok to false, and success by setting *ok to true.

If base is 0, the C language convention is used: if the string view begins with "0x", base 16 is used; otherwise, if the string view begins with "0", base 8 is used; otherwise, base 10 is used.

The string conversion will always happen in the 'C' locale. For locale dependent conversion use QLocale::toUInt()

This function was introduced in Qt 6.0.

See also QString::toUInt().

[since 6.0] ulong QStringView::toULong(bool *ok = nullptr, int base = 10) const

Returns the string view converted to an unsigned long using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If ok is not nullptr, failure is reported by setting *ok to false, and success by setting *ok to true.

If base is 0, the C language convention is used: if the string view begins with "0x", base 16 is used; otherwise, if the string view begins with "0", base 8 is used; otherwise, base 10 is used.

The string conversion will always happen in the 'C' locale. For locale dependent conversion use QLocale::toULongLong()

This function was introduced in Qt 6.0.

See also QString::toULong().

[since 6.0] qulonglong QStringView::toULongLong(bool *ok = nullptr, int base = 10) const

Returns the string view converted to an unsigned long long using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If ok is not nullptr, failure is reported by setting *ok to false, and success by setting *ok to true.

If base is 0, the C language convention is used: if the string view begins with "0x", base 16 is used; otherwise, if the string view begins with "0", base 8 is used; otherwise, base 10 is used.

The string conversion will always happen in the 'C' locale. For locale dependent conversion use QLocale::toULongLong()

This function was introduced in Qt 6.0.

See also QString::toULongLong().

[since 6.0] ushort QStringView::toUShort(bool *ok = nullptr, int base = 10) const

Returns the string view converted to an unsigned short using base base, which is 10 by default and must be between 2 and 36, or 0. Returns 0 if the conversion fails.

If ok is not nullptr, failure is reported by setting *ok to false, and success by setting *ok to true.

If base is 0, the C language convention is used: if the string view begins with "0x", base 16 is used; otherwise, if the string view begins with "0", base 8 is used; otherwise, base 10 is used.

The string conversion will always happen in the 'C' locale. For locale dependent conversion use QLocale::toUShort()

This function was introduced in Qt 6.0.

See also QString::toUShort().

QList<uint> QStringView::toUcs4() const

Returns a UCS-4/UTF-32 representation of the string view as a QList<uint>.

UCS-4 is a Unicode codec and therefore it is lossless. All characters from this string view will be encoded in UCS-4. Any invalid sequence of code units in this string view is replaced by the Unicode replacement character (QChar::ReplacementCharacter, which corresponds to U+FFFD).

The returned list is not 0-terminated.

See also toUtf8(), toLatin1(), toLocal8Bit(), and QStringEncoder.

QByteArray QStringView::toUtf8() const

Returns a UTF-8 representation of the string view as a QByteArray.

UTF-8 is a Unicode codec and can represent all characters in a Unicode string like QString.

See also toLatin1(), toLocal8Bit(), and QStringEncoder.

qsizetype QStringView::toWCharArray(wchar_t *array) const

Transcribes this string view into the given array.

The caller is responsible for ensuring array is large enough to hold the wchar_t encoding of this string view (allocating the array with the same length as the string view is always sufficient). The array is encoded in UTF-16 on platforms where wchar_t is 2 bytes wide (e.g. Windows); otherwise (Unix systems), wchar_t is assumed to be 4 bytes wide and the data is written in UCS-4.

Returns the number of wchar_t entries written to array.

See also QString::toWCharArray().

[noexcept] QStringView QStringView::trimmed() const

Strips leading and trailing whitespace and returns the result.

Whitespace means any character for which QChar::isSpace() returns true. This includes the ASCII characters '\t', '\n', '\v', '\f', '\r', and ' '.

[constexpr noexcept] void QStringView::truncate(qsizetype length)

Truncates this string view to length length.

Same as *this = left(length).

See also mid(), left(), right(), chopped(), and chop().

[constexpr noexcept] const QStringView::storage_type *QStringView::utf16() const

Returns a const pointer to the first character in the string view.

storage_type is char16_t.

See also begin(), end(), and data().

[noexcept, since 6.7] std::u16string_view QStringView::operator std::u16string_view() const

Converts this QStringView object to a std::u16string_view object. The returned view will have the same data pointer and length of this view.

This function was introduced in Qt 6.7.

[constexpr] QChar QStringView::operator[](qsizetype n) const

Returns the character at position n in this string view.

The behavior is undefined if n is negative or not less than size().

See also at(), front(), and back().