string.h

来自「C程序设计经典教程第5版程序示例,比较适合初级c语言的学生」· C头文件 代码 · 共 77 行

// Fig. 22.9: String.h
// String class definition.
#ifndef STRING_H
#define STRING_H

#include <iostream>
using std::ostream;
using std::istream;

class String
{
   friend ostream &operator<<( ostream &, const String & );
   friend istream &operator>>( istream &, String & );
public:
   String( const char * = "" ); // conversion/default constructor
   String( const String & ); // copy constructor
   ~String(); // destructor

   const String &operator=( const String & ); // assignment operator
   const String &operator+=( const String & ); // concatenation operator

   bool operator!() const; // is String empty?
   bool operator==( const String & ) const; // test s1 == s2
   bool operator<( const String & ) const; // test s1 < s2

   // test s1 != s2
   bool operator!=( const String &right ) const
   { 
      return !( *this == right ); 
   } // end function operator!=

   // test s1 > s2
   bool operator>( const String &right ) const
   { 
      return right < *this; 
   } // end function operator>
 
   // test s1 <= s2
   bool operator<=( const String &right ) const
   { 
      return !( right < *this ); 
   } // end function operator <=

   // test s1 >= s2
   bool operator>=( const String &right ) const
   { 
      return !( *this < right ); 
   } // end function operator>=

   char &operator[]( int ); // subscript operator (modifiable lvalue)
   char operator[]( int ) const; // subscript operator (rvalue)
   String operator()( int, int = 0 ) const; // return a substring
   int getLength() const; // return string length
private:
   int length; // string length (not counting null terminator)
   char *sPtr; // pointer to start of pointer-based string

   void setString( const char * ); // utility function
}; // end class String

#endif

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