operator< (<string>)

如果在运算符左侧的字符串对象小于对于右侧的字符串，测试对象。

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
   );

参数

• _Left
  对.样式字符串或类型 basic_string 对象要比较。

• _Right
  对.样式字符串或类型 basic_string 对象要比较。

返回值

true，如果在运算符左侧的字符串对象与右侧的字符串对象字典地小于;否则 false。

备注

在字符串之间的一个字典比较的字符比较这些字符直到:

• 它发现两个对应的字符不相等，并且，它们的比较结果执行因为比较在字符串之间。

• 它不查找不相等，但是，一个字符串比其他具有多个字符，因此，较短的字符串大于较长字符串被视为较少。

• 它不查找不相等和发现字符串具有字符数相同，并且，因此字符串相等。

示例

// string_op_lt.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 the string s2." << endl;
   else
      cout << "The string s1 is not less than the string s2." << endl;

   // Second member function: comparison between left-hand object
   // of type basic_string & right-hand object of C-syle string type
   if ( s1 < s3 )
      cout << "The string s1 is less than the string s3." << endl;
   else
      cout << "The string s1 is not less than the string s3." << endl;

   // Third member function: comparison between left-hand object
   // of C-syle string type & right-hand object of type basic_string
   if ( s3 < s2 )
      cout << "The string s3 is less than the string s2." << endl;
   else
      cout << "The string s3 is not less than the string s2." << endl;
}

要求

标头: <string>

命名空间: std

请参见

参考

string::operator<