INFO: STL Sample for the basic_string size and resize Functions

ID: Q157433

The information in this article applies to:

The Standard C++ Library, used with:
- Microsoft Visual C++, 32-bit Editions, versions 4.2, 5.0, 6.0

SUMMARY

The sample code below illustrates how to use the basic_string size() and resize() STL function(s) in Visual C++.

MORE INFORMATION

Required Header


   <string>

Prototype


   size_type size() const;

   void resize(size_type n, E c = E());


   resize is defined in header xstring which is included indirectly.

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

The size() function returns the length of the sequence.

The resize() function changes the size to the length specified by the first parameter. If the sequence is made longer, the function appends elements with the value of the second parameter. This value defaults to a null. The output of the sample code shows spaces for the null characters. operator<< reads the size of string and outputs each character in the string one at a time.

Sample Code


////////////////////////////////////////////////////////////////////// 
// 
// Compile options needed: /GX
// 
// <filename> :  size.cpp
// 
// Functions:
// 
//    size()
//    resize() ; Defined in header xstring which is included indirectly.
// 
// Written by Linda Koontz
// of Microsoft Product Support Services,
// Copyright (c) 1996 Microsoft Corporation. All rights reserved.
////////////////////////////////////////////////////////////////////// 

/* Compile options needed: /GX
*/ 
#include <iostream>
#include <string>

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

void main()


    string TestString = "1111122222333334444455555";
    cout << TestString << "\n  size: " << TestString.size() << endl;
    TestString.resize(5);
    cout << TestString << "\n  size: " << TestString.size() << endl;
    TestString.resize(10);
    cout << TestString << "\n  size: " << TestString.size() << endl;
    TestString.resize(15,'6');
    cout << TestString << "\n  size: " << TestString.size() << endl;

}

Output is:


1111122222333334444455555
  size: 25
11111
  size: 5
11111
  size: 10
11111     66666
  size: 15

REFERENCES

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

Additional query words: STL STLSample size resize

Keywords : kbcode kbVC420 kbVC500 kbVC600 kbDSupport STLIss
Version : winnt:4.2,5.0,6.0
Platform : winnt
Issue type : kbinfo