comparison operators - C++ Reference

comparison operators

function

bool operator== ( const string& lhs, const string& rhs ); bool operator== ( const char* lhs, const string& rhs ); bool operator== ( const string& lhs, const char* rhs ); bool operator!= ( const string& lhs, const string& rhs ); bool operator!= ( const char* lhs, const string& rhs ); bool operator!= ( const string& lhs, const char* rhs ); bool operator< ( const string& lhs, const string& rhs ); bool operator< ( const char* lhs, const string& rhs ); bool operator< ( const string& lhs, const char* rhs ); bool operator> ( const string& lhs, const string& rhs ); bool operator> ( const char* lhs, const string& rhs ); bool operator> ( const string& lhs, const char* rhs ); bool operator<= ( const string& lhs, const string& rhs ); bool operator<= ( const char* lhs, const string& rhs ); bool operator<= ( const string& lhs, const char* rhs ); bool operator>= ( const string& lhs, const string& rhs ); bool operator>= ( const char* lhs, const string& rhs ); bool operator>= ( const string& lhs, const char* rhs );

<string>

String comparison operators

These overloaded global operator functions perform the appropriate comparison operation, between lhs and rhs.

These function depend on the value returned by string member compare.

Parameters

lhs, rhs: Both lhs and rhs can be either a string object or a null-terminated character sequence (a c-string), although at least one of them has to be a string object. In the case of a c-string, an equivalent string object is temporarily constructed for the comparison.

Return Value

Depending on the operator, the function returns:

operator	returns
`operator==`	`lhs.compare(rhs)==0`
`operator!=`	`lhs.compare(rhs)!=0`
`operator<`	`lhs.compare(rhs)<0`
`operator>`	`lhs.compare(rhs)>0`
`operator<=`	`lhs.compare(rhs)<=0`
`operator>=`	`lhs.compare(rhs)>=0`

Basic template declarations

template<class charT, chass traits, class Allocator>
  bool operator== ( const basic_string<charT,traits,Allocator>& lhs,
                    const basic_string<charT,traits,Allocator>& rhs );
template<class charT, chass traits, class Allocator>
  bool operator== ( const charT* lhs,
                    const basic_string<charT,traits,Allocator>& rhs );
template<class charT, chass traits, class Allocator>
  bool operator== ( const basic_string<charT,traits,Allocator>& rhs,
                    const charT* lhs );

template<class charT, chass traits, class Allocator>
  bool operator!= ( const basic_string<charT,traits,Allocator>& lhs,
                    const basic_string<charT,traits,Allocator>& rhs );
template<class charT, chass traits, class Allocator>
  bool operator!= ( const charT* lhs,
                    const basic_string<charT,traits,Allocator>& rhs );
template<class charT, chass traits, class Allocator>
  bool operator!= ( const basic_string<charT,traits,Allocator>& rhs,
                    const charT* lhs );

template<class charT, chass traits, class Allocator>
  bool operator< ( const basic_string<charT,traits,Allocator>& lhs,
                    const basic_string<charT,traits,Allocator>& rhs );
template<class charT, chass traits, class Allocator>
  bool operator< ( const charT* lhs,
                    const basic_string<charT,traits,Allocator>& rhs );
template<class charT, chass traits, class Allocator>
  bool operator< ( const basic_string<charT,traits,Allocator>& rhs,
                    const charT* lhs );

template<class charT, chass traits, class Allocator>
  bool operator> ( const basic_string<charT,traits,Allocator>& lhs,
                    const basic_string<charT,traits,Allocator>& rhs );
template<class charT, chass traits, class Allocator>
  bool operator> ( const charT* lhs,
                    const basic_string<charT,traits,Allocator>& rhs );
template<class charT, chass traits, class Allocator>
  bool operator> ( const basic_string<charT,traits,Allocator>& rhs,
                    const charT* lhs );

template<class charT, chass traits, class Allocator>
  bool operator<= ( const basic_string<charT,traits,Allocator>& lhs,
                    const basic_string<charT,traits,Allocator>& rhs );
template<class charT, chass traits, class Allocator>
  bool operator<= ( const charT* lhs,
                    const basic_string<charT,traits,Allocator>& rhs );
template<class charT, chass traits, class Allocator>
  bool operator<= ( const basic_string<charT,traits,Allocator>& rhs,
                    const charT* lhs );

template<class charT, chass traits, class Allocator>
  bool operator>= ( const basic_string<charT,traits,Allocator>& lhs,
                    const basic_string<charT,traits,Allocator>& rhs );
template<class charT, chass traits, class Allocator>
  bool operator>= ( const charT* lhs,
                    const basic_string<charT,traits,Allocator>& rhs );
template<class charT, chass traits, class Allocator>
  bool operator>= ( const basic_string<charT,traits,Allocator>& rhs,
                    const charT* lhs );


		C++ : Reference : Strings library : operators

Parameters

Return Value

Basic template declarations

See also