How to use the basic_string size and resize Standard Template Library (STL) functions 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.
////////////////////////////////////////////////////////////////////// 

#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