QChar Class | Qt Core (original) (raw)
This class is strongly comparable.
The contents of the byte array is interpreted as UTF-8.
Member Function Documentation
[constexpr noexcept] QChar::QChar()
Constructs a null QChar ('\0').
See also isNull().
[constexpr noexcept] QChar::QChar(QChar::SpecialCharacter ch)
Constructs a QChar for the predefined character value ch.
Note: Since Qt 6.9, implicit conversions are disabled for this constructor. That means it accepts only the constructor argument type and not everything that implicitly converts to it. A backwards-compatible fix is to explicitly cast to one of the supported argument types of QChar constructors.
[constexpr noexcept] QChar::QChar(QLatin1Char ch)
Constructs a QChar corresponding to ASCII/Latin-1 character ch.
Note: Since Qt 6.9, implicit conversions are disabled for this constructor. That means it accepts only the constructor argument type and not everything that implicitly converts to it. A backwards-compatible fix is to explicitly cast to one of the supported argument types of QChar constructors.
[constexpr noexcept] QChar::QChar(char ch)
Constructs a QChar corresponding to ASCII/Latin-1 character ch.
Note: This constructor is not available when QT_NO_CAST_FROM_ASCII is defined.
Note: Since Qt 6.9, implicit conversions are disabled for this constructor. That means it accepts only the constructor argument type and not everything that implicitly converts to it. A backwards-compatible fix is to explicitly cast to one of the supported argument types of QChar constructors.
See also QT_NO_CAST_FROM_ASCII.
[constexpr noexcept] QChar::QChar(char16_t ch)
Constructs a QChar corresponding to the UTF-16 character ch.
Note: Since Qt 6.9, implicit conversions are disabled for this constructor. That means it accepts only the constructor argument type and not everything that implicitly converts to it. A backwards-compatible fix is to explicitly cast to one of the supported argument types of QChar constructors.
[default] QChar::QChar(char32_t code)
Constructs a QChar for the character with Unicode code point code.
Note: Since Qt 6.9, implicit conversions are disabled for this constructor. That means it accepts only the constructor argument type and not everything that implicitly converts to it. A backwards-compatible fix is to explicitly cast to one of the supported argument types of QChar constructors.
[explicit constexpr noexcept] QChar::QChar(int code)
Constructs a QChar for the character with Unicode code point code.
Note: Since Qt 6.9, implicit conversions are disabled for this constructor. That means it accepts only the constructor argument type and not everything that implicitly converts to it. A backwards-compatible fix is to explicitly cast to one of the supported argument types of QChar constructors.
[constexpr noexcept] QChar::QChar(short code)
Constructs a QChar for the character with Unicode code point code.
Note: Since Qt 6.9, implicit conversions are disabled for this constructor. That means it accepts only the constructor argument type and not everything that implicitly converts to it. A backwards-compatible fix is to explicitly cast to one of the supported argument types of QChar constructors.
[explicit constexpr noexcept] QChar::QChar(uchar ch)
Constructs a QChar corresponding to ASCII/Latin-1 character ch.
Note: This constructor is not available when QT_NO_CAST_FROM_ASCII or QT_RESTRICTED_CAST_FROM_ASCII is defined.
Note: Since Qt 6.9, implicit conversions are disabled for this constructor. That means it accepts only the constructor argument type and not everything that implicitly converts to it. A backwards-compatible fix is to explicitly cast to one of the supported argument types of QChar constructors.
See also QT_NO_CAST_FROM_ASCII and QT_RESTRICTED_CAST_FROM_ASCII.
[explicit constexpr noexcept] QChar::QChar(uint code)
Constructs a QChar for the character with Unicode code point code.
Note: Since Qt 6.9, implicit conversions are disabled for this constructor. That means it accepts only the constructor argument type and not everything that implicitly converts to it. A backwards-compatible fix is to explicitly cast to one of the supported argument types of QChar constructors.
[constexpr noexcept] QChar::QChar(ushort code)
Constructs a QChar for the character with Unicode code point code.
Note: Since Qt 6.9, implicit conversions are disabled for this constructor. That means it accepts only the constructor argument type and not everything that implicitly converts to it. A backwards-compatible fix is to explicitly cast to one of the supported argument types of QChar constructors.
[constexpr noexcept] QChar::QChar(wchar_t ch)
Constructs a QChar corresponding to the wide character ch.
Note: This constructor is only available on Windows.
Note: Since Qt 6.9, implicit conversions are disabled for this constructor. That means it accepts only the constructor argument type and not everything that implicitly converts to it. A backwards-compatible fix is to explicitly cast to one of the supported argument types of QChar constructors.
[explicit constexpr noexcept] QChar::QChar(uchar cell, uchar row)
Constructs a QChar for Unicode cell cell in row row.
[noexcept] QChar::Category QChar::category() const
Returns the character's category.
[static noexcept] QChar::Category QChar::category(char32_t ucs4)
This is an overloaded function.
Returns the category of the UCS-4-encoded character specified by ucs4.
Note: Before Qt 6, this function took a uint argument.
[constexpr noexcept] uchar QChar::cell() const
Returns the cell (least significant byte) of the Unicode character.
See also row().
[noexcept] unsigned char QChar::combiningClass() const
Returns the combining class for the character as defined in the Unicode standard. This is mainly useful as a positioning hint for marks attached to a base character.
The Qt text rendering engine uses this information to correctly position non-spacing marks around a base character.
[static noexcept] unsigned char QChar::combiningClass(char32_t ucs4)
This is an overloaded function.
Returns the combining class for the UCS-4-encoded character specified by ucs4, as defined in the Unicode standard.
Note: Before Qt 6, this function took a uint argument.
[static noexcept] QChar::UnicodeVersion QChar::currentUnicodeVersion()
Returns the most recent supported Unicode version.
QString QChar::decomposition() const
Decomposes a character into it's constituent parts. Returns an empty string if no decomposition exists.
[static] QString QChar::decomposition(char32_t ucs4)
This is an overloaded function.
Decomposes the UCS-4-encoded character specified by ucs4 into it's constituent parts. Returns an empty string if no decomposition exists.
Note: Before Qt 6, this function took a uint argument.
[noexcept] QChar::Decomposition QChar::decompositionTag() const
Returns the tag defining the composition of the character. Returns QChar::NoDecomposition if no decomposition exists.
[static noexcept] QChar::Decomposition QChar::decompositionTag(char32_t ucs4)
This is an overloaded function.
Returns the tag defining the composition of the UCS-4-encoded character specified by ucs4. Returns QChar::NoDecomposition if no decomposition exists.
Note: Before Qt 6, this function took a uint argument.
[noexcept] int QChar::digitValue() const
Returns the numeric value of the digit, or -1 if the character is not a digit.
[static noexcept] int QChar::digitValue(char32_t ucs4)
This is an overloaded function.
Returns the numeric value of the digit specified by the UCS-4-encoded character, ucs4, or -1 if the character is not a digit.
Note: Before Qt 6, this function took a uint argument.
[noexcept] QChar::Direction QChar::direction() const
Returns the character's direction.
[static noexcept] QChar::Direction QChar::direction(char32_t ucs4)
This is an overloaded function.
Returns the direction of the UCS-4-encoded character specified by ucs4.
Note: Before Qt 6, this function took a uint argument.
[static constexpr noexcept] QChar QChar::fromLatin1(char c)
Converts the Latin-1 character c to its equivalent QChar. This is mainly useful for non-internationalized software.
An alternative is to use QLatin1Char.
See also toLatin1() and unicode().
[static constexpr noexcept, since 6.0] QChar QChar::fromUcs2(char16_t c)
Constructs a QChar from UTF-16 character c.
This function was introduced in Qt 6.0.
See also fromUcs4().
[static constexpr noexcept, since 6.0] auto QChar::fromUcs4(char32_t c)
Returns an anonymous struct that
- contains a
char16_t chars[2]array, - can be implicitly converted to a QStringView, and
- iterated over with a C++11 ranged for loop.
If c requires surrogates, chars[0] contains the high surrogate and chars[1] the low surrogate, and the QStringView has size 2. Otherwise, chars[0] contains c and chars[1] is null, and the QStringView has size 1.
This allows easy use of the result:
for (char16_t c16 : QChar::fromUcs4(ch)) use(c16);
This function was introduced in Qt 6.0.
See also fromUcs2() and requiresSurrogates().
[noexcept] bool QChar::hasMirrored() const
Returns true if the character should be reversed if the text direction is reversed; otherwise returns false.
A bit faster equivalent of (ch.mirroredChar() != ch).
See also mirroredChar().
[static noexcept] bool QChar::hasMirrored(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 should be reversed if the text direction is reversed; otherwise returns false.
A bit faster equivalent of (QChar::mirroredChar(ucs4) != ucs4).
Note: Before Qt 6, this function took a uint argument.
See also mirroredChar().
[static constexpr noexcept] char16_t QChar::highSurrogate(char32_t ucs4)
Returns the high surrogate part of a UCS-4-encoded code point. The returned result is undefined if ucs4 is smaller than 0x10000.
Note: Before Qt 6, this function took a uint argument and returned ushort.
[constexpr noexcept] bool QChar::isDigit() const
Returns true if the character is a decimal digit (Number_DecimalDigit); otherwise returns false.
See also isNumber().
[static constexpr noexcept] bool QChar::isDigit(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is a decimal digit (Number_DecimalDigit); otherwise returns false.
Note: Before Qt 6, this function took a uint argument.
See also isNumber().
[constexpr noexcept] bool QChar::isHighSurrogate() const
Returns true if the QChar is the high part of a UTF16 surrogate (for example if its code point is in range [0xd800..0xdbff]); false otherwise.
[static constexpr noexcept] bool QChar::isHighSurrogate(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is the high part of a UTF16 surrogate (for example if its code point is in range [0xd800..0xdbff]); false otherwise.
Note: Before Qt 6, this function took a uint argument.
[constexpr noexcept] bool QChar::isLetter() const
Returns true if the character is a letter (Letter_* categories); otherwise returns false.
[static constexpr noexcept] bool QChar::isLetter(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is a letter (Letter_* categories); otherwise returns false.
Note: Before Qt 6, this function took a uint argument.
[constexpr noexcept] bool QChar::isLetterOrNumber() const
Returns true if the character is a letter or number (Letter_* or Number_* categories); otherwise returns false.
[static constexpr noexcept] bool QChar::isLetterOrNumber(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is a letter or number (Letter_* or Number_* categories); otherwise returns false.
Note: Before Qt 6, this function took a uint argument.
[constexpr noexcept] bool QChar::isLowSurrogate() const
Returns true if the QChar is the low part of a UTF16 surrogate (for example if its code point is in range [0xdc00..0xdfff]); false otherwise.
[static constexpr noexcept] bool QChar::isLowSurrogate(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is the low part of a UTF16 surrogate (for example if its code point is in range [0xdc00..0xdfff]); false otherwise.
Note: Before Qt 6, this function took a uint argument.
[constexpr noexcept] bool QChar::isLower() const
Returns true if the character is a lowercase letter, for example category() is Letter_Lowercase.
See also isUpper(), toLower(), and toUpper().
[static constexpr noexcept] bool QChar::isLower(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is a lowercase letter, for example category() is Letter_Lowercase.
Note: Before Qt 6, this function took a uint argument.
See also isUpper(), toLower(), and toUpper().
[noexcept] bool QChar::isMark() const
Returns true if the character is a mark (Mark_* categories); otherwise returns false.
See QChar::Category for more information regarding marks.
[static noexcept] bool QChar::isMark(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is a mark (Mark_* categories); otherwise returns false.
Note: Before Qt 6, this function took a uint argument.
[constexpr noexcept] bool QChar::isNonCharacter() const
Returns true if the QChar is a non-character; false otherwise.
Unicode has a certain number of code points that are classified as "non-characters:" that is, they can be used for internal purposes in applications but cannot be used for text interchange. Those are the last two entries each Unicode Plane ([0xfffe..0xffff], [0x1fffe..0x1ffff], etc.) as well as the entries in range [0xfdd0..0xfdef].
[static constexpr noexcept] bool QChar::isNonCharacter(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is a non-character; false otherwise.
Unicode has a certain number of code points that are classified as "non-characters:" that is, they can be used for internal purposes in applications but cannot be used for text interchange. Those are the last two entries each Unicode Plane ([0xfffe..0xffff], [0x1fffe..0x1ffff], etc.) as well as the entries in range [0xfdd0..0xfdef].
Note: Before Qt 6, this function took a uint argument.
[constexpr noexcept] bool QChar::isNull() const
Returns true if the character is the Unicode character 0x0000 ('\0'); otherwise returns false.
[constexpr noexcept] bool QChar::isNumber() const
Returns true if the character is a number (Number_* categories, not just 0-9); otherwise returns false.
See also isDigit().
[static constexpr noexcept] bool QChar::isNumber(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is a number (Number_* categories, not just 0-9); otherwise returns false.
Note: Before Qt 6, this function took a uint argument.
See also isDigit().
[noexcept] bool QChar::isPrint() const
Returns true if the character is a printable character; otherwise returns false. This is any character not of category Other_*.
Note that this gives no indication of whether the character is available in a particular font.
[static noexcept] bool QChar::isPrint(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is a printable character; otherwise returns false. This is any character not of category Other_*.
Note that this gives no indication of whether the character is available in a particular font.
Note: Before Qt 6, this function took a uint argument.
[noexcept] bool QChar::isPunct() const
Returns true if the character is a punctuation mark (Punctuation_* categories); otherwise returns false.
[static noexcept] bool QChar::isPunct(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is a punctuation mark (Punctuation_* categories); otherwise returns false.
Note: Before Qt 6, this function took a uint argument.
[constexpr noexcept] bool QChar::isSpace() const
Returns true if the character is a separator character (Separator_* categories or certain code points from Other_Control category); otherwise returns false.
[static constexpr noexcept] bool QChar::isSpace(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is a separator character (Separator_* categories or certain code points from Other_Control category); otherwise returns false.
Note: Before Qt 6, this function took a uint argument.
[constexpr noexcept] bool QChar::isSurrogate() const
Returns true if the QChar contains a code point that is in either the high or the low part of the UTF-16 surrogate range (for example if its code point is in range [0xd800..0xdfff]); false otherwise.
[static constexpr noexcept] bool QChar::isSurrogate(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 contains a code point that is in either the high or the low part of the UTF-16 surrogate range (for example if its code point is in range [0xd800..0xdfff]); false otherwise.
Note: Before Qt 6, this function took a uint argument.
[noexcept] bool QChar::isSymbol() const
Returns true if the character is a symbol (Symbol_* categories); otherwise returns false.
[static noexcept] bool QChar::isSymbol(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is a symbol (Symbol_* categories); otherwise returns false.
Note: Before Qt 6, this function took a uint argument.
[constexpr noexcept] bool QChar::isTitleCase() const
Returns true if the character is a titlecase letter, for example category() is Letter_Titlecase.
See also isLower(), toUpper(), toLower(), and toTitleCase().
[static constexpr noexcept] bool QChar::isTitleCase(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is a titlecase letter, for example category() is Letter_Titlecase.
Note: Before Qt 6, this function took a uint argument.
See also isLower(), toUpper(), toLower(), and toTitleCase().
[constexpr noexcept] bool QChar::isUpper() const
Returns true if the character is an uppercase letter, for example category() is Letter_Uppercase.
See also isLower(), toUpper(), and toLower().
[static constexpr noexcept] bool QChar::isUpper(char32_t ucs4)
This is an overloaded function.
Returns true if the UCS-4-encoded character specified by ucs4 is an uppercase letter, for example category() is Letter_Uppercase.
Note: Before Qt 6, this function took a uint argument.
See also isLower(), toUpper(), and toLower().
[noexcept] QChar::JoiningType QChar::joiningType() const
Returns information about the joining type attributes of the character (needed for certain languages such as Arabic or Syriac).
[static noexcept] QChar::JoiningType QChar::joiningType(char32_t ucs4)
This is an overloaded function.
Returns information about the joining type attributes of the UCS-4-encoded character specified by ucs4 (needed for certain languages such as Arabic or Syriac).
Note: Before Qt 6, this function took a uint argument.
[static constexpr noexcept] char16_t QChar::lowSurrogate(char32_t ucs4)
Returns the low surrogate part of a UCS-4-encoded code point. The returned result is undefined if ucs4 is smaller than 0x10000.
Note: Before Qt 6, this function took a uint argument and returned ushort.
[noexcept] QChar QChar::mirroredChar() const
Returns the mirrored character if this character is a mirrored character; otherwise returns the character itself.
See also hasMirrored().
[static noexcept] char32_t QChar::mirroredChar(char32_t ucs4)
This is an overloaded function.
Returns the mirrored character if the UCS-4-encoded character specified by ucs4 is a mirrored character; otherwise returns the character itself.
Note: Before Qt 6, this function took a uint argument and returned uint.
See also hasMirrored().
[static constexpr noexcept] bool QChar::requiresSurrogates(char32_t ucs4)
Returns true if the UCS-4-encoded character specified by ucs4 can be split into the high and low parts of a UTF16 surrogate (for example if its code point is greater than or equals to 0x10000); false otherwise.
Note: Before Qt 6, this function took a uint argument.
[constexpr noexcept] uchar QChar::row() const
Returns the row (most significant byte) of the Unicode character.
See also cell().
[noexcept] QChar::Script QChar::script() const
Returns the Unicode script property value for this character.
[static noexcept] QChar::Script QChar::script(char32_t ucs4)
This is an overloaded function.
Returns the Unicode script property value for the character specified in its UCS-4-encoded form as ucs4.
Note: Before Qt 6, this function took a uint argument.
[static constexpr noexcept] char32_t QChar::surrogateToUcs4(char16_t high, char16_t low)
Converts a UTF16 surrogate pair with the given high and low values to it's UCS-4-encoded code point.
Note: Before Qt 6, this function took ushort arguments and returned uint.
[static constexpr noexcept] char32_t QChar::surrogateToUcs4(QChar high, QChar low)
This is an overloaded function.
Converts a UTF16 surrogate pair (high, low) to it's UCS-4-encoded code point.
Note: Before Qt 6, this function returned uint.
[noexcept] QChar QChar::toCaseFolded() const
Returns the case folded equivalent of the character. For most Unicode characters this is the same as toLower().
[static noexcept] char32_t QChar::toCaseFolded(char32_t ucs4)
This is an overloaded function.
Returns the case folded equivalent of the UCS-4-encoded character specified by ucs4. For most Unicode characters this is the same as toLower().
Note: Before Qt 6, this function took a uint argument and returned uint.
[constexpr noexcept] char QChar::toLatin1() const
Returns the Latin-1 character equivalent to the QChar, or 0. This is mainly useful for non-internationalized software.
Note: It is not possible to distinguish a non-Latin-1 character from a Latin-1 0 (NUL) character. Prefer to use unicode(), which does not have this ambiguity.
See also unicode().
[noexcept] QChar QChar::toLower() const
Returns the lowercase equivalent if the character is uppercase or titlecase; otherwise returns the character itself.
[static noexcept] char32_t QChar::toLower(char32_t ucs4)
This is an overloaded function.
Returns the lowercase equivalent of the UCS-4-encoded character specified by ucs4 if the character is uppercase or titlecase; otherwise returns the character itself.
Note: Before Qt 6, this function took a uint argument and returned uint.
[noexcept] QChar QChar::toTitleCase() const
Returns the title case equivalent if the character is lowercase or uppercase; otherwise returns the character itself.
[static noexcept] char32_t QChar::toTitleCase(char32_t ucs4)
This is an overloaded function.
Returns the title case equivalent of the UCS-4-encoded character specified by ucs4 if the character is lowercase or uppercase; otherwise returns the character itself.
Note: Before Qt 6, this function took a uint argument and returned uint.
[noexcept] QChar QChar::toUpper() const
Returns the uppercase equivalent if the character is lowercase or titlecase; otherwise returns the character itself.
Note: This function also returns the original character in the rare case of the uppercase form of the character requiring two or more characters.
See also QString::toUpper().
[static noexcept] char32_t QChar::toUpper(char32_t ucs4)
This is an overloaded function.
Returns the uppercase equivalent of the UCS-4-encoded character specified by ucs4 if the character is lowercase or titlecase; otherwise returns the character itself.
Note: This function also returns the original character in the rare case of the uppercase form of the character requiring two or more characters.
Note: Before Qt 6, this function took a uint argument and returned uint.
See also QString::toUpper().
[constexpr noexcept] char16_t &QChar::unicode()
Returns a reference to the numeric Unicode value of the QChar.
[constexpr noexcept] char16_t QChar::unicode() const
Returns the numeric Unicode value of the QChar.
[noexcept] QChar::UnicodeVersion QChar::unicodeVersion() const
Returns the Unicode version that introduced this character.
[static noexcept] QChar::UnicodeVersion QChar::unicodeVersion(char32_t ucs4)
This is an overloaded function.
Returns the Unicode version that introduced the character specified in its UCS-4-encoded form as ucs4.
Note: Before Qt 6, this function took a uint argument.