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basic_string::compare

Effectue une comparaison respectant la casse avec une chaîne spécifiée pour déterminer si les deux chaînes sont égales ou s'il est lexicographique inférieure à l'autre.

int compare(
    const basic_string<CharType, Traits, Allocator>& _Str
) const;
int compare(
    size_type _Pos1, 
    size_type _Num1,
    const basic_string<CharType, Traits, Allocator>& _Str
) const;
int compare(
    size_type _Pos1,
    size_type _Num1,
    const basic_string<CharType, Traits, Allocator>& _Str, 
    size_type _Off, 
    size_type _Count
) const;
int compare(
    const value_type* _Ptr
) const;
int compare(
    size_type _Pos1,
    size_type _Num1,
    const value_type* _Ptr
) const;
int compare(
    size_type _Pos1,
    size_type _Num1,
    const value_type* _Ptr
    size_type _Num2
) const;

Paramètres

  • _Str
    La chaîne qui doit être comparée à la chaîne d'opérande.

  • _Pos1
    L'index de la chaîne d'opérande à laquelle la comparaison commence.

  • _Num1
    Le nombre maximal de caractères de la chaîne d'opérande à comparer.

  • _Num2
    Le nombre maximal de caractères de la chaîne de paramètre à comparer.

  • _Off
    L'index de la chaîne de paramètre à laquelle la comparaison commence.

  • _Count
    Le nombre maximal de caractères de la chaîne de paramètre à comparer.

  • _Ptr
    La chaîne c à comparer à la chaîne d'opérande.

Valeur de retour

Une valeur négative si la chaîne d'opérande est inférieure à la chaîne de paramètre ; zéro si les deux chaînes sont égales ; ou une valeur positive si la chaîne d'opérande est supérieure à la chaîne de paramètre.

Notes

Les fonctions membres de compare comparent l'un ou l'autre de l'ensemble ou une partie du paramètre et l'opérande chaînes en fonction duquel dans utilisé.

La comparaison exécutée respecte la casse.

Exemple

// basic_string_compare.cpp
// compile with: /EHsc
#include <string>
#include <iostream>

int main( ) 
{
   using namespace std;

   // The first member function compares
   // an operand string to a parameter string
   int comp1;
   string s1o ( "CAB" );
   string s1p ( "CAB" );
   cout << "The operand string is: " << s1o << endl;
   cout << "The parameter string is: " << s1p << endl;
   comp1 = s1o.compare ( s1p );
   if ( comp1 < 0 )
      cout << "The operand string is less than "
           << "the parameter string." << endl;
   else if ( comp1 == 0 )
      cout << "The operand string is equal to "
           << "the parameter string." << endl;
   else
      cout << "The operand string is greater than "
           << "the parameter string." << endl;
   cout << endl;

   // The second member function compares part of
   // an operand string to a parameter string
   int comp2a, comp2b;
   string s2o ( "AACAB" );
   string s2p ( "CAB" );
   cout << "The operand string is: " << s2o << endl;
   cout << "The parameter string is: " << s2p << endl;
   comp2a = s2o.compare (  2 , 3 , s2p );
   if ( comp2a < 0 )
      cout << "The last three characters of "
           << "the operand string\n are less than "
           << "the parameter string." << endl;
   else if ( comp2a == 0 )
      cout << "The last three characters of "
           << "the operand string\n are equal to "
           << "the parameter string." << endl;
   else
      cout << "The last three characters of "
           << "the operand string\n is greater than "
           << "the parameter string." << endl;

   comp2b = s2o.compare (  0 , 3 , s2p );
   if ( comp2b < 0 )
      cout << "The first three characters of "
           << "the operand string\n are less than "
           << "the parameter string." << endl;
   else if ( comp2b == 0 )
      cout << "The first three characters of "
           << "the operand string\n are equal to "
           << "the parameter string." << endl;
   else
      cout << "The first three characters of "
           << "the operand string\n is greater than "
           << "the parameter string." << endl;
   cout << endl;

   // The third member function compares part of
   // an operand string to part of a parameter string
   int comp3a;
   string s3o ( "AACAB" );
   string s3p ( "DCABD" );
   cout << "The operand string is: " << s3o << endl;
   cout << "The parameter string is: " << s3p << endl;
   comp3a = s3o.compare (  2 , 3 , s3p , 1 , 3 );
   if ( comp3a < 0 )
      cout << "The three characters from position 2 of "
           << "the operand string are less than\n "
           << "the 3 characters parameter string " 
           << "from position 1." << endl;
   else if ( comp3a == 0 )
      cout << "The three characters from position 2 of "
           << "the operand string are equal to\n "
           << "the 3 characters parameter string " 
           << "from position 1." << endl;
   else
      cout << "The three characters from position 2 of "
           << "the operand string is greater than\n "
           << "the 3 characters parameter string " 
           << "from position 1." << endl;
   cout << endl;

   // The fourth member function compares
   // an operand string to a parameter C-string
   int comp4a;
   string s4o ( "ABC" );
   const char* cs4p = "DEF";
   cout << "The operand string is: " << s4o << endl;
   cout << "The parameter C-string is: " << cs4p << endl;
   comp4a = s4o.compare ( cs4p );
   if ( comp4a < 0 )
      cout << "The operand string is less than "
           << "the parameter C-string." << endl;
   else if ( comp4a == 0 )
      cout << "The operand string is equal to "
           << "the parameter C-string." << endl;
   else
      cout << "The operand string is greater than "
           << "the parameter C-string." << endl;
   cout << endl;

   // The fifth member function compares part of
   // an operand string to a parameter C-string
   int comp5a;
   string s5o ( "AACAB" );
   const char* cs5p = "CAB";
   cout << "The operand string is: " << s5o << endl;
   cout << "The parameter string is: " << cs5p << endl;
   comp5a = s5o.compare (  2 , 3 , s2p );
   if ( comp5a < 0 )
      cout << "The last three characters of "
           << "the operand string\n are less than "
           << "the parameter C-string." << endl;
   else if ( comp5a == 0 )
      cout << "The last three characters of "
           << "the operand string\n are equal to "
           << "the parameter C-string." << endl;
   else
      cout << "The last three characters of "
           << "the operand string\n is greater than "
           << "the parameter C-string." << endl;
   cout << endl;

   // The sixth member function compares part of
   // an operand string to part of an equal length of
   // a parameter C-string
   int comp6a;
   string s6o ( "AACAB" );
   const char* cs6p = "ACAB";
   cout << "The operand string is: " << s6o << endl;
   cout << "The parameter C-string is: " << cs6p << endl;
   comp6a = s6o.compare (  1 , 3 , cs6p , 3 );
   if ( comp6a < 0 )
      cout << "The 3 characters from position 1 of "
           << "the operand string are less than\n "
           << "the first 3 characters of the parameter C-string." 
           << endl;
   else if ( comp6a == 0 )
      cout << "The 3 characters from position 2 of "
           << "the operand string are equal to\n "
           << "the first 3 characters of the parameter C-string." 
           <<  endl;
   else
      cout << "The 3 characters from position 2 of "
           << "the operand string is greater than\n "
           << "the first 3 characters of the parameter C-string." 
           << endl;
   cout << endl;
}
  
  
  
  
  
  
  

Configuration requise

en-tête : <string>

l'espace de noms : DST

Voir aussi

Référence

basic_string Class