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operator<= (in <string>)

Tests if the string object on the left side of the operator is less than or equal to the string object on the right side.

template<class CharType, class Traits, class Allocator> 
   bool operator<=( 
      const basic_string<CharType, Traits, Allocator>& _Left, 
      const basic_string<CharType, Traits, Allocator>& _Right 
   ); 
template<class CharType, class Traits, class Allocator> 
   bool operator<=( 
      const basic_string<CharType, Traits, Allocator>& _Left, 
      const CharType *_Right 
   ); 
template<class CharType, class Traits, class Allocator> 
   bool operator<=( 
      const CharType *_Left, 
      const basic_string<CharType, Traits, Allocator>& _Right 
   );

_Left

A C-style string or an object of type basic_string to be compared.

_Right

A C-style string or an object of type basic_string to be compared.

true if the string object on the left side of the operator is lexicographically less than or equal to the string object on the right side; otherwise false.

A lexicographical comparison between strings compares them character by character until:

  • It finds two corresponding characters unequal, and the result of their comparison is taken as the result of the comparison between the strings.

  • It finds no inequalities, but one string has more characters than the other, and the shorter string is considered less than the longer string.

  • It finds no inequalities and finds that the strings have the same number of characters, so the strings are equal.

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

int main( ) 
{
   using namespace std;

   // Declaring an objects of type basic_string<char>
   string s1 ( "strict" );
   string s2 ( "strum" );
   cout << "The basic_string s1 = " << s1 << "." << endl;
   cout << "The basic_string s2 = " << s2 << "." << endl;

   // Declaring a C-style string
   char *s3 = "strict";
   cout << "The C-style string s3 = " << s3 << "." << endl;

   // First member function: comparison between left-side object
   // of type basic_string & right-side object of type basic_string
   if ( s1 <= s2 )
      cout << "The string s1 is less than or equal to "
           << "the string s2." << endl;
   else
      cout << "The string s1 is greater than "
           << "the string s2." << endl;

   // Second member function: comparison between left-side object
   // of type basic_string & right-side object of C-syle string type
   if ( s1 <= s3 )
      cout << "The string s1 is less than or equal to "
           << "the string s3." << endl;
   else
      cout << "The string s1 is greater than "
           << "the string s3." << endl;

   // Third member function: comparison between left-side object
   // of C-syle string type  & right-side object of type basic_string
   if ( s2 <= s3 )
      cout << "The string s2 is less than or equal to "
           << "the string s3." << endl;
   else
      cout << "The string s2 is greater than "
           << "the string s3." << endl;
}
The basic_string s1 = strict.
The basic_string s2 = strum.
The C-style string s3 = strict.
The string s1 is less than or equal to the string s2.
The string s1 is less than or equal to the string s3.
The string s2 is greater than the string s3.

Header: <string>

Namespace: std

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