Q158207: STL Sample for the string::operator+ Function

Article: Q158207
Product(s): Microsoft C Compiler
Version(s): 4.2,5.0,6.0
Operating System(s): 
Keyword(s): kbcode kbVC420 kbVC500 kbVC600 kbDSupport
Last Modified: 29-APR-2002

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The information in this article applies to:

- The Standard C++ Library, used with:
   - Microsoft Visual C++, 32-bit Enterprise Edition, versions 4.2, 5.0, 6.0 
   - Microsoft Visual C++, 32-bit Professional Edition, versions 4.2, 5.0, 6.0 
   - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 
   - Microsoft Visual C++.NET (2002) 
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SUMMARY
=======

The sample code below illustrates how to use the string::operator+ STL function
in Visual C++.

MORE INFORMATION
================

Required Header
---------------

     <string>

Prototype
---------

     Function 1:
         template<class _E, class _TYPE, class _A> inline
         basic_string<_E, _TYPE, _A>
         operator+(const basic_string<_E, _TYPE, _A>& LString,
                   const _E *RCharArray);

     Function 2:
         template<class _E, class _TYPE, class _A> inline
         basic_string<_E, _TYPE, _A>
         operator+(const _E *LCharArray,
                   const basic_string<_E, _TYPE, _A>& RString);

     Function 3:
         template<class _E, class _TYPE, class _A> inline
         basic_string<_E, _TYPE, _A>
         operator+(const basic_string<_E, _TYPE, _A>& LString,
                   const _E RChar);

     Function 4:
         template<class _E, class _TYPE, class _A> inline
         basic_string<_E, _TYPE, _A>
         operator+(const _E LChar,
                   const basic_string<_E, _TYPE, _A>& RString);

     Function 5:
         template<class _E, class _TYPE, class _A> inline
         basic_string<_E, _TYPE, _A>
         operator+(const basic_string<_E, _TYPE, _A>& LString,
                   const basic_string<_E, _TYPE, _A>& RString);

NOTE: The class/parameter names in the prototype may not match the version in the
header file. Some have been modified to improve readability.

Description:
------------

There are five versions of the string::operator+ function. Two functions are used
to concatenate a null-terminated character array and a basic_string. Two
functions are used to concatenate a character and a basic_string. The last
function is used to concatenate two basic_string variables.

Sample Code
-----------

  ////////////////////////////////////////////////////////////////////// 
  // 
  // Compile options needed: /GX
  // 
  // StringPlus.cpp : Illustrates how to use the operator+ to concatenate
  //                  a null-terminated character array and a basic_string,
  //                  how to concatenate a character and a basic_string,
  //                  and how to concatenate two basic_string variables.
  // 
  // Functions:
  // 
  //    operator+ : Concatenates a null-terminated character array and
  //                a basic_string.
  //    operator+ : Concatenates a character array and a basic_string.
  //    operator+ : Concatenates two basic_string variables.
  // 
  // Written by Derek Jamison
  // of Microsoft Product Support Services,
  // Copyright (c) 1996 Microsoft Corporation. All rights reserved.
  ////////////////////////////////////////////////////////////////////// 

  #pragma warning(disable:4786)
  #include <string>
  #include <iostream>
  using namespace std;

  #if _MSC_VER > 1020   // if VC++ version is > 4.2
     using namespace std;  // std c++ libs implemented in std
     #endif

  void main()

  {

     string result;
     string S1="ABC";
     string S2="DEF";
     char CP1[]="GHI";
     char C='J';

     cout << "S1 is " << S1 << endl;
     cout << "S2 is " << S2 << endl;
     cout << "CP1 is " << CP1 << endl;
     cout << "C is " << C << endl;

     result=S1+CP1;                           // Function 1  (ABCGHI)
     cout << "S1+CP1 is " << result << endl;

     result=CP1+S1;                           // Function 2  (GHIABC)
     cout << "CP1+S1 is " << result << endl;

     result=S1+S2;                            // Function 3  (ABCDEF)
     cout << "S1+S2 is " << result << endl;

     result=S1+C;                             // Function 4  (ABCJ)
     cout << "S1+C is " << result << endl;

     result=C+S1;                             // Function 5  (JABC)
     cout << "C+S1 is " << result << endl;

  }

Program Output is:

  S1 is ABC
  S2 is DEF
  CP1 is GHI
  C is J
  S1+CP1 is ABCGHI
  CP1+S1 is GHIABC
  S1+S2 is ABCDEF
  S1+C is ABCJ
  C+S1 is JABC

REFERENCES
==========

Visual C++ Books On Line: Visual C++ Books:C/C++:Standard C++ Library Reference.

Additional query words: STL STLSample operator+ string

======================================================================
Keywords          : kbcode kbVC420 kbVC500 kbVC600 kbDSupport 
Technology        : kbVCsearch kbAudDeveloper kbVCLibrary
Version           : :4.2,5.0,6.0
Issue type        : kbinfo

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