operator<= (in <string>)

測試,如果左側的字串物件小於或等於右邊的字串物件。

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
   );

參數

  • _Left
    C. 式字串或型別要比較的 basic_string 物件。

  • _Right
    C. 式字串或型別要比較的 basic_string 物件。

傳回值

true ,如果左側的字串物件 Dictionary 會小於或等於右邊的字串物件,否則 false

備註

在字串之間的字典比較字串的比較它們字元直到:

  • 找到兩個相對應的字元視為不相同,因此,其比較的結果會因比較字串之間。

  • 它不會尋找不相等,不過,一個字串大於另一個有多個字元,然後,較短的字串比較長的字串會視為小於。

  • 它不會尋找不相等並尋找字串具有相同數目的字元,因此,字串相等。

範例

// 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;
}
  
  
  
  
  
  

需求

標題: <string>

命名空間: std

請參閱

參考

string::operator<=