Qt Toolkit - QString Class

# QString Class Reference

The QString class provides an abstraction of the classic C zero-terminated char array (char*). More...

`#include <qstring.h>`

Inherits QByteArray.

List of all member functions.

## Public Members

- QString ()
- QString ( int size )
- QString ( const QString & s )
- QString ( const char * str )
- QString ( const char * str, uint maxlen )
- QString& operator= ( const QString & s )
- QString& operator= ( const char * str )
- bool isNull () const
- bool isEmpty () const
- uint length () const
- bool resize ( uint newlen )
- bool truncate ( uint pos )
- bool fill ( char c, int len = -1 )
- QString copy () const
- QString& sprintf ( const char * format, ... )
- int find ( char c, int index=0, bool cs=TRUE ) const
- int find ( const char * str, int index=0, bool cs=TRUE ) const
- int find ( const QRegExp &, int index=0 ) const
- int findRev ( char c, int index=-1, bool cs=TRUE ) const
- int findRev ( const char * str, int index=-1, bool cs=TRUE ) const
- int findRev ( const QRegExp &, int index=-1 ) const
- int contains ( char c, bool cs=TRUE ) const
- int contains ( const char * str, bool cs=TRUE ) const
- int contains ( const QRegExp & ) const
- QString left ( uint len ) const
- QString right ( uint len ) const
- QString mid ( uint index, uint len ) const
- QString leftJustify ( uint width, char fill=' ', bool trunc=FALSE ) const
- QString rightJustify ( uint width, char fill=' ', bool trunc=FALSE ) const
- QString lower () const
- QString upper () const
- QString stripWhiteSpace () const
- QString simplifyWhiteSpace () const
- QString& insert ( uint index, const char * )
- QString& insert ( uint index, char )
- QString& append ( const char * )
- QString& prepend ( const char * )
- QString& remove ( uint index, uint len )
- QString& replace ( uint index, uint len, const char * )
- QString& replace ( const QRegExp &, const char * )
- short toShort ( bool * ok=0 ) const
- ushort toUShort ( bool * ok=0 ) const
- int toInt ( bool * ok=0 ) const
- uint toUInt ( bool * ok=0 ) const
- long toLong ( bool * ok=0 ) const
- ulong toULong ( bool * ok=0 ) const
- float toFloat ( bool * ok=0 ) const
- double toDouble ( bool * ok=0 ) const
- QString& setStr ( const char * s )
- QString& setNum ( short )
- QString& setNum ( ushort )
- QString& setNum ( int )
- QString& setNum ( uint )
- QString& setNum ( long )
- QString& setNum ( ulong )
- QString& setNum ( float, char f='g', int prec=6 )
- QString& setNum ( double, char f='g', int prec=6 )
- bool setExpand ( uint index, char c )
- operator const char* ()const
- QString& operator+= ( const char * str )
- QString& operator+= ( char c )

## Related Functions

(Note that these are not member functions.)

- void * memmove (void * dst, const void * src, uint len)
- char * qstrdup (const char * str)
- uint strlen (const char * str)
- char * strcpy (char * dst, const char * str)
- char * qstrncpy (char * dst, const char * src, uint len)
- int strcmp (const char * str1, const char * str2)
- int strncmp (const char * str1, const char * str2, uint len)
- int stricmp (const char * str1, const char * str2)
- int strnicmp (const char * str1, const char * str2, uint len)
- QDataStream & operator<< (QDataStream & s, const QString & str)
- QDataStream & operator>> (QDataStream & s, QString & str)
- bool operator== (const QString & s1, const QString & s2)
- bool operator== (const QString & s1, const char * s2)
- bool operator== (const char * s1, const QString & s2)
- bool operator!= (const QString & s1, const QString & s2)
- bool operator!= (const QString & s1, const char * s2)
- bool operator!= (const char * s1, const QString & s2)
- bool operator< (const QString & s1, const char * s2)
- bool operator< (const char * s1, const QString & s2)
- bool operator<= (const QString & s1, const char * s2)
- bool operator<= (const char * s1, const QString & s2)
- bool operator> (const QString & s1, const char * s2)
- bool operator> (const char * s1, const QString & s2)
- bool operator>= (const QString & s1, const char * s2)
- bool operator>= (const char * s1, const QString & s2)
- QString operator+ (const QString & s1, const QString & s2)
- QString operator+ (const QString & s1, const char * s2)
- QString operator+ (const char * s1, const QString & s2)
- QString operator+ (const QString & s, char c)
- QString operator+ (char c, const QString & s)

## Detailed Description

The QString class provides an abstraction of the classic C zero-terminated char array (char*).

QString inherits QByteArray, which is defined as QArray<char>.

Since QString is a QArray, it uses explicit sharing with a reference count.

Note that for the QString methods that take a const char * parameter the results are undefined if the QString is not zero-terminated. It is legal for the const char * parameter to be 0.

A QString that has not been assigned to anything is null, i.e. both the length and data pointer is 0. A QString that references the empty string ("", a single '\0' char) is empty. Both null and empty QStrings are legal parameters to the methods. Assigning const char * 0 to QString gives a null QString.

See also: Shared classes

Examples: table/table.cpp dclock/dclock.cpp grapher/grapher.cpp forever/forever.cpp dirview/dirview.cpp desktop/desktop.cpp tooltip/tooltip.cpp drawdemo/drawdemo.cpp movies/main.cpp picture/picture.cpp xform/xform.cpp application/application.cpp pref/pref.cpp progress/progress.cpp layout/layout.cpp qmag/qmag.cpp showimg/showimg.cpp biff/biff.cpp widgets/widgets.cpp

## Member Function Documentation

### QString::QString ()

Constructs a null string.

See also: isNull().

### QString::QString ( const QString & s )

Constructs a shallow copy s.

See also: assign().

### QString::QString ( const char * str )

Constructs a string that is a deep copy of str.

If str is 0 a null string is created.

See also: isNull().

### QString::QString ( const char * str, uint maxlen )

Constructs a string that is a deep copy of str, that is no more than maxlen bytes long including the '\0'-terminator.

Example:

        QString str("helloworld",6); // Assigns "hello" to str.

If str contains a 0 byte within the first maxlen bytes, the resulting QString will be terminated by the 0. If str is 0 a null string is created.

See also: isNull().

### QString::QString ( int size )

Constructs a string with room for size characters, including the '\0'-terminator. Makes a null string if size == 0.

If size > 0, then the first and last characters in the string are initialized to '\0'. All other characters are uninitialized.

See also: resize() and isNull().

### QString::operator const char * () const

Returns the string data.

### QString& QString::append ( const char * str )

Appends str to the string and returns a reference to the string. Equivalent to operator+=().

Examples: dirview/dirview.cpp

### int QString::contains ( char c, bool cs=TRUE ) const

Returns the number of times the character c occurs in the string.

The match is case sensitive if cs is TRUE, or case insensitive if cs if FALSE.

### int QString::contains ( const QRegExp & rx ) const

Counts the number of overlapping occurrences of rx in the string.

Example:

        QString s = "banana and panama";
        QRegExp r = QRegExp("a[nm]a", TRUE, FALSE);
        s.contains( r );                            // 4 matches

See also: find() and findRev().

### int QString::contains ( const char * str, bool cs=TRUE ) const

Returns the number of times str occurs in the string.

The match is case sensitive if cs is TRUE, or case insensitive if cs if FALSE.

This function counts overlapping substrings, for example, "banana" contains two occurrences of "ana".

See also: findRev().

### QString QString::copy () const

Returns a deep copy of this string.

See also: detach().

### bool QString::fill ( char c, int len = -1 )

Fills the string with len bytes of value c, followed by a '\0'-terminator.

If len is negative, then the current string length is used.

Returns FALSE is len is nonnegative and there is no memory to resize the string, otherwise TRUE is returned.

### int QString::find ( char c, int index=0, bool cs=TRUE ) const

Finds the first occurrence of the character c, starting at position index.

The search is case sensitive if cs is TRUE, or case insensitive if cs is FALSE.

Returns the position of c, or -1 if c could not be found.

### int QString::find ( const QRegExp & rx, int index=0 ) const

Finds the first occurrence of the regular expression rx, starting at position index.

Returns the position of the next match, or -1 if rx was not found.

### int QString::find ( const char * str, int index=0, bool cs=TRUE ) const

Finds the first occurrence of the string str, starting at position index.

The search is case sensitive if cs is TRUE, or case insensitive if cs is FALSE.

Returns the position of str, or -1 if str could not be found.

### int QString::findRev ( char c, int index=-1, bool cs=TRUE ) const

Finds the first occurrence of the character c, starting at position index and searching backwards.

The search is case sensitive if cs is TRUE, or case insensitive if cs is FALSE.

Returns the position of c, or -1 if c could not be found.

### int QString::findRev ( const QRegExp & rx, int index=-1 ) const

Finds the first occurrence of the regular expression rx, starting at position index and searching backwards.

The search will start from the end of the string if index is negative.

Returns the position of the next match (backwards), or -1 if rx was not found.

### int QString::findRev ( const char * str, int index=-1, bool cs=TRUE ) const

Finds the first occurrence of the string str, starting at position index and searching backwards.

The search is case sensitive if cs is TRUE, or case insensitive if cs is FALSE.

Returns the position of str, or -1 if str could not be found.

### QString & QString::insert ( uint index, char c )

Insert c into the string at (before) position index and returns a reference to the string.

If index is beyond the end of the string, the string is extended with spaces (ASCII 32) to length index and c is then appended.

Example:

        QString s = "Yes";
        s.insert( 3, '!');                          // s == "Yes!"

See also: remove() and replace().

### QString & QString::insert ( uint index, const char * s )

Insert s into the string before position index.

If index is beyond the end of the string, the string is extended with spaces (ASCII 32) to length index and s is then appended.

        QString s = "I like fish";
        s.insert( 2, "don't ");                     // s == "I don't like fish"
        s = "x";
        s.insert( 3, "yz" );                        // s == "x  yz"

Examples: xform/xform.cpp

### bool QString::isEmpty () const

Returns TRUE if the string is empty, i.e. if length() == 0. An empty string is not always a null string.

See example in isNull().

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

Examples: application/application.cpp qmag/qmag.cpp showimg/showimg.cpp

### bool QString::isNull () const

Returns TRUE if the string is null, i.e. if data() == 0. A null string is also an empty string.

Example:

        QString a;          // a.data() == 0,  a.size() == 0, a.length() == 0
        QString b == "";    // b.data() == "", b.size() == 1, b.length() == 0
        a.isNull();         // TRUE, because a.data() == 0
        a.isEmpty();        // TRUE, because a.length() == 0
        b.isNull();         // FALSE, because b.data() == ""
        b.isEmpty();        // TRUE, because b.length() == 0

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

### QString QString::left ( uint len ) const

Returns a substring that contains the len leftmost characters of the string.

The whole string is returned if len exceeds the length of the string.

Example:

        QString s = "Pineapple";
        QString t = s.left( 4 );                    // t == "Pine"

See also: right() and mid().

### QString QString::leftJustify ( uint width, char fill=' ', bool truncate=FALSE ) const

Returns a string of length width (plus '\0') that contains this string and padded by the fill character.

If the length of the string exceeds width and truncate is FALSE, then the returned string is a copy of the string. If the length of the string exceeds width and truncate is TRUE, then the returned string is a left(width).

Example:

        QString s("apple");
        QString t = s.leftJustify(8, '.');          // t == "apple..."

See also: rightJustify().

### uint QString::length () const

Returns the length of the string, excluding the '\0'-terminator. Equivalent to calling `strlen(data()).`

Null strings and empty strings have zero length.

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

Examples: showimg/showimg.cpp

### QString QString::lower () const

Returns a new string that is the string converted to lower case.

Presently it only handles 7-bit ASCII, or whatever tolower() handles (if $LC_CTYPE is set, most UNIX systems do the Right Thing).

Example:

        QString s("TeX");
        QString t = s.lower();                      // t == "tex"

See also: upper().

### QString QString::mid ( uint index, uint len ) const

Returns a substring that contains the len characters of this string, starting at position index.

Returns a null string if the string is empty or index is out of range. Returns the whole string from index if index+len exceeds the length of the string.

Example:

        QString s = "Two pineapples";
        QString t = s.mid( 4, 4 );                  // t == "pine"

See also: left() and right().

Examples: qmag/qmag.cpp

### QString & QString::operator+= ( char c )

Appends c to the string and returns a reference to the string.

### QString& QString::operator+= ( const char * str )

Appends str to the string and returns a reference to the string.

### QString & QString::operator= ( const QString & s )

Assigns a shallow copy of s to this string and returns a reference to this string.

### QString & QString::operator= ( const char * str )

Assigns a deep copy of str to this string and returns a reference to this string.

If str is 0 a null string is created.

See also: isNull().

### QString & QString::prepend ( const char * s )

Prepend \s to the string. Equivalent to insert(0,s).

See also: insert().

### QString & QString::remove ( uint index, uint len )

Removes len characters starting at position index from the string and returns a reference to the string.

If index is too big, nothing happens. If index is valid, but len is too large, the rest of the string is removed.

        QString s = "Montreal";
        s.remove( 1, 4 );
        // s == "Meal"

See also: insert() and replace().

### QString & QString::replace ( const QRegExp & rx, const char * str )

Replaces every occurrence of rx in the string with str. Returns a reference to the string.

Example:

        QString s = "banana";
        s.replace( QRegExp("a.*a"), "" );           // becomes "b"

        QString s = "banana";
        s.replace( QRegExp("^[bn]a"), " " );        // becomes " nana"

        QString s = "banana";
        s.replace( QRegExp("^[bn]a"), "" );         // NOTE! becomes ""

Examples: qmag/qmag.cpp

### QString & QString::replace ( uint index, uint len, const char * s )

Replaces len characters starting at position index from the string with s, and returns a reference to the string.

If index is too big, nothing is deleted and s is inserted at the end of the string. If index is valid, but len is too large, str replaces the rest of the string.

        QString s = "Say yes!";
        s.replace( 4, 3, "NO" );                    // s == "Say NO!"

See also: insert() and remove().

### bool QString::resize ( uint len )

Extends or shrinks the string to len bytes, including the '\0'-terminator.

A \0-terminator is set at position `len - 1` unless `len == 0`.

Example:

        QString s = "resize this string";
        s.resize( 7 );                              // s == "resize"

See also: truncate().

### QString QString::right ( uint len ) const

Returns a substring that contains the len rightmost characters of the string.

The whole string is returned if len exceeds the length of the string.

Example:

        QString s = "Pineapple";
        QString t = s.right( 5 );                   // t == "apple"

See also: left() and mid().

### QString QString::rightJustify ( uint width, char fill=' ', bool truncate=FALSE ) const

Returns a string of length width (plus '\0') that contains pad characters followed by the string.

If the length of the string exceeds width and truncate is FALSE, then the returned string is a copy of the string. If the length of the string exceeds width and truncate is TRUE, then the returned string is a right(width).

Example:

        QString s("pie");
        QString t = s.rightJustify(8, '.');         // t == ".....pie"

See also: leftJustify().

### bool QString::setExpand ( uint index, char c )

Sets the character at position index to c and expands the string if necessary, filling with spaces.

Returns FALSE if this index was out of range and the string could not be expanded, otherwise TRUE.

### QString & QString::setNum ( double n, char f='g', int prec=6 )

Sets the string to the printed value of n.

Arguments:

- f is the format specifier: 'f', 'F', 'e', 'E', 'g', 'G' (same as sprintf()).
- prec is the precision.

Returns a reference to the string.

### QString & QString::setNum ( float n, char f='g', int prec=6 )

Sets the string to the printed value of n.

Arguments:

- f is the format specifier: 'f', 'F', 'e', 'E', 'g', 'G' (same as sprintf()).
- prec is the precision.

Returns a reference to the string.

### QString & QString::setNum ( int n )

Sets the string to the printed value of n and returns a reference to the string.

### QString & QString::setNum ( long n )

Sets the string to the printed value of n and returns a reference to the string.

### QString & QString::setNum ( short n )

Sets the string to the printed value of n and returns a reference to the string.

### QString & QString::setNum ( uint n )

Sets the string to the printed unsigned value of n and returns a reference to the string.

### QString & QString::setNum ( ulong n )

Sets the string to the printed unsigned value of n and returns a reference to the string.

### QString & QString::setNum ( ushort n )

Sets the string to the printed unsigned value of n and returns a reference to the string.

### QString & QString::setStr ( const char * str )

Makes a deep copy of str. Returns a reference to the string.

### QString QString::simplifyWhiteSpace () const

Returns a new string that has white space removed from the start and the end, plus any sequence of internal white space replaced with a single space (ASCII 32).

White space means any ASCII code 9, 10, 11, 12, 13 or 32.

        QString s = "  lots\t of\nwhite    space ";
        QString t = s.simplifyWhiteSpace();         // t == "lots of white space"

See also: stripWhiteSpace().

### QString & QString::sprintf ( const char * format, ... )

Implemented as a call to the native vsprintf() (see your C-library manual).

If your string is shorter than 256 characters, this sprintf() calls resize(256) to decrease the chance of memory corruption. The string is resized back to its natural length before sprintf() returns.

Example:

        QString s;
        s.sprintf( "%d - %s", 1, "first" );         // result < 256 chars

        QString big( 25000 );                       // very long string
        big.sprintf( "%d - %s", 2, longString );    // result < 25000 chars

Warning: All vsprintf() implementations will write past the end of the target string (*this) if the format specification and arguments happen to be longer than the target string, and some will also fail if the target string is longer than some arbitrary implementation limit.

Giving user-supplied arguments to sprintf() is begging for trouble. Sooner or later someone will paste a 3000-character line into your application.

Examples: dclock/dclock.cpp forever/forever.cpp tooltip/tooltip.cpp drawdemo/drawdemo.cpp movies/main.cpp picture/picture.cpp xform/xform.cpp application/application.cpp pref/pref.cpp progress/progress.cpp layout/layout.cpp qmag/qmag.cpp showimg/showimg.cpp widgets/widgets.cpp

### QString QString::stripWhiteSpace () const

Returns a new string that has white space removed from the start and the end.

White space means any ASCII code 9, 10, 11, 12, 13 or 32.

Example:

        QString s = " space ";
        QString t = s.stripWhiteSpace();            // t == "space"

See also: simplifyWhiteSpace().

### double QString::toDouble ( bool * ok=0 ) const

Returns the string converted to a `double` value.

If ok is non-null, *ok is set to TRUE if there are no conceivable errors, and FALSE if the string is not a number at all, or if it has trailing garbage.

### float QString::toFloat ( bool * ok=0 ) const

Returns the string converted to a `float` value.

If ok is non-null, *ok is set to TRUE if there are no conceivable errors, and FALSE if the string is not a number at all, or if it has trailing garbage.

### int QString::toInt ( bool * ok=0 ) const

Returns the string converted to a `int` value.

If ok is non-null, *ok is set to TRUE if there are no conceivable errors, and FALSE if the string is not a number at all, or if it has trailing garbage.

### long QString::toLong ( bool * ok=0 ) const

Returns the string converted to a `long` value.

If ok is non-null, *ok is set to TRUE if there are no conceivable errors, and FALSE if the string is not a number at all, or if it has trailing garbage.

### short QString::toShort ( bool * ok=0 ) const

Returns the string converted to a `short` value.

If ok is non-null, *ok is set to TRUE if there are no conceivable errors, and FALSE if the string is not a number at all, or if it has trailing garbage.

### uint QString::toUInt ( bool * ok=0 ) const

Returns the string converted to an `unsigned int` value.

If ok is non-null, *ok is set to TRUE if there are no conceivable errors, and FALSE if the string is not a number at all, or if it has trailing garbage.

### ulong QString::toULong ( bool * ok=0 ) const

Returns the string converted to an `unsigned long` value.

If ok is non-null, *ok is set to TRUE if there are no conceivable errors, and FALSE if the string is not a number at all, or if it has trailing garbage.

### ushort QString::toUShort ( bool * ok=0 ) const

Returns the string converted to an `unsigned short` value.

If ok is non-null, *ok is set to TRUE if there are no conceivable errors, and FALSE if the string is not a number at all, or if it has trailing garbage.

### bool QString::truncate ( uint pos )

Truncates the string at position pos.

Equivalent to calling `resize(pos+1).`

Example:

        QString s = "truncate this string";
        s.truncate( 5 );                            // s == "trunc"

See also: resize().

### QString QString::upper () const

Returns a new string that is the string converted to upper case.

Presently it only handles 7-bit ASCII, or whatever toupper() handles (if $LC_CTYPE is set, most UNIX systems do the Right Thing).

Example:

        QString s("TeX");
        QString t = s.upper();                      // t == "TEX"

See also: lower().

## Related Functions

### void * memmove (void * dst, const void * src, uint len)

This function is normally part of the C library. Qt implements memmove() for platforms that do not have it.

memmove() copies len bytes from src into dst. The data is copied correctly even if src and dst overlap.

### char * qstrdup (const char * str)

Returns a duplicate string.

Allocates space for a copy of str (using `new),` copies it, and returns a pointer to the copy. If src is null, it immediately returns 0.

### uint strlen (const char * str)

A safe strlen() function that overrides the one defined by the C library. The original strlen() function has been renamed cstrlen().

Returns the number of characters in str, or 0 if str is null.

### char * strcpy (char * dst, const char * str)

A safe strcpy() function that overrides the one defined by the C library. The original strcpy() function has been renamed cstrcpy().

Copies all characters (including \0) from str into dst and returns a pointer to dst. If src is null, it immediately returns 0.

See also: qstrncpy().

### char * qstrncpy (char * dst, const char * src, uint len)

A safe strncpy() function.

Copies all characters up to len bytes from str into dst and returns a pointer to dst. Guarantees that dst is \0-terminated. If src is null, it immediately returns 0.

See also: strcpy().

### int strcmp (const char * str1, const char * str2)

A safe strcmp() function that overrides the one defined by the C library. The original strcmp() function has been renamed cstrcmp().

Compares str1 and str2. Returns a negative value if str1 is less than str2, 0 if str1 is equal to str2 or a positive value if str1 is greater than str2.

Special case I: Returns 0 if str1 and str2 are both null.

Special case II: Returns a random nonzero value if str1 is null or str2 is null (but not both).

See also: strncmp(), stricmp() and strnicmp().

Examples: desktop/desktop.cpp

### int strncmp (const char * str1, const char * str2, uint len)

A safe strncmp() function that overrides the one defined by the C library. The original strncmp() function has been renamed cstrncmp().

Compares str1 and str2 up to len bytes.

Returns a negative value if str1 is less than str2, 0 if str1 is equal to str2 or a positive value if str1 is greater than str2.

Special case I: Returns 0 if str1 and str2 are both null.

Special case II: Returns a random nonzero value if str1 is null or str2 is null (but not both).

See also: strcmp(), stricmp() and strnicmp().

### int stricmp (const char * str1, const char * str2)

A safe stricmp() function that overrides the one defined by the C library, if the C library has one.

Compares str1 and str2 ignoring the case.

Returns a negative value if str1 is less than str2, 0 if str1 is equal to str2 or a positive value if str1 is greater than str2.

Special case I: Returns 0 if str1 and str2 are both null.

Special case II: Returns a random nonzero value if str1 is null or str2 is null (but not both).

See also: strcmp(), strncmp() and strnicmp().

### int strnicmp (const char * str1, const char * str2, uint len)

A safe strnicmp() function that overrides the one defined by the C library, if the C library has one.

Compares str1 and str2 up to len bytes ignoring the case.

Returns a negative value if str1 is less than str2, 0 if str1 is equal to str2 or a positive value if str1 is greater than str2.

Special case I: Returns 0 if str1 and str2 are both null.

Special case II: Returns a random nonzero value if str1 is null or str2 is null (but not both).

See also: strcmp(), strncmp() and stricmp().

### QDataStream & operator<< (QDataStream & s, const QString & str)

Writes a string to the stream.

Output format: [length (Q_UINT32) data...].

### QDataStream & operator>> (QDataStream & s, QString & str)

Reads a string from the stream.

### bool operator== (const QString & s1, const QString & s2)

Returns TRUE if the two strings are equal, or FALSE if they are different.

Equivalent to `strcmp(s1,s2) == 0`

### bool operator== (const QString & s1, const char * s2)

Returns TRUE if the two strings are equal, or FALSE if they are different.

Equivalent to `strcmp(s1,s2) == 0`

### bool operator== (const char * s1, const QString & s2)

Returns TRUE if the two strings are equal, or FALSE if they are different.

Equivalent to `strcmp(s1,s2) == 0`

### bool operator!= (const QString & s1, const QString & s2)

Returns TRUE if the two strings are different, or FALSE if they are equal.

Equivalent to `strcmp(s1,s2) != 0`

### bool operator!= (const QString & s1, const char * s2)

Returns TRUE if the two strings are different, or FALSE if they are equal.

Equivalent to `strcmp(s1,s2) != 0`

### bool operator!= (const char * s1, const QString & s2)

Returns TRUE if the two strings are different, or FALSE if they are equal.

Equivalent to `strcmp(s1,s2) != 0`

### bool operator< (const QString & s1, const char * s2)

Returns TRUE if s1 is alphabetically less than s2, otherwise FALSE.

Equivalent to `strcmp(s1,s2) < 0`

### bool operator< (const char * s1, const QString & s2)

Returns TRUE if s1 is alphabetically less than s2, otherwise FALSE.

Equivalent to `strcmp(s1,s2) < 0`

### bool operator<= (const QString & s1, const char * s2)

Returns TRUE if s1 is alphabetically less than or equal to s2, otherwise FALSE.

Equivalent to `strcmp(s1,s2) <= 0`

### bool operator<= (const char * s1, const QString & s2)

Returns TRUE if s1 is alphabetically less than or equal to s2, otherwise FALSE.

Equivalent to `strcmp(s1,s2) <= 0`

### bool operator> (const QString & s1, const char * s2)

Returns TRUE if s1 is alphabetically greater than s2, otherwise FALSE.

Equivalent to `strcmp(s1,s2) > 0`

### bool operator> (const char * s1, const QString & s2)

Returns TRUE if s1 is alphabetically greater than s2, otherwise FALSE.

Equivalent to `strcmp(s1,s2) > 0`

### bool operator>= (const QString & s1, const char * s2)

Returns TRUE if s1 is alphabetically greater than or equal to s2, otherwise FALSE.

Equivalent to `strcmp(s1,s2) >= 0`

### bool operator>= (const char * s1, const QString & s2)

Returns TRUE if s1 is alphabetically greater than or equal to s2, otherwise FALSE.

Equivalent to `strcmp(s1,s2) >= 0`

### QString operator+ (const QString & s1, const QString & s2)

Returns the concatenated string of s1 and s2.

### QString operator+ (const QString & s1, const char * s2)

Returns the concatenated string of s1 and s2.

### QString operator+ (const char * s1, const QString & s2)

Returns the concatenated string of s1 and s2.

### QString operator+ (const QString & s, char c)

Returns the concatenated string of s and c.

### QString operator+ (char c, const QString & s)

Returns the concatenated string of c and s.

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This file is part of the Qt toolkit, copyright © 1995-99 Troll Tech, all rights reserved.

It was generated from the following files:

- qstring.h: 1999/02/17
- qstring.cpp: 1998/09/15