INFO: count Function

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

SUMMARY

The following sample code illustrates how to use the set::count STL

function in Visual C++. 

MORE INFORMATION

Required Header

   <set> 

Prototype

   template<class _K, class _Pr, class _A>
   class set {
   public:
   // Function 1:

      size_type count(const _K& _Kv) const;

   } 

Description

Sample Code

////////////////////////////////////////////////////////////////////// 
// 
// Compile options needed: -GX
// 
// SetCount.cpp:
//      Illustrates how to use the count function to determine how
//      many elements have a particular key.
// 
// Functions:
// 
//    count        Returns the number of elements in the controlled
//                 sequence that have a particular key.
// 
// Written by Derek Jamison
// of Microsoft Technical Support,
// Copyright (c) 1996 Microsoft Corporation. All rights reserved.
////////////////////////////////////////////////////////////////////// 

#pragma warning(disable:4786)

#include <set>
#include <iostream>

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

typedef set<int,less<int>,allocator<int> > SET_INT;

void truefalse(int x)

{
  cout << (x?"True":"False") << endl;
}

void main() {

  SET_INT s1;
  SET_INT::_Pairib pib;
  cout << "s1.insert(5)" << endl;
  pib=s1.insert(5);
  cout << "Inserted element: ";
  truefalse(pib.second);  // True

  cout << "s1.insert(5)" << endl;
  pib=s1.insert(5);
  cout << "Inserted element: ";
  truefalse(pib.second);  // True

  cout << "s1.insert(8)" << endl;
  s1.insert(8);

  cout << "s1.insert(12)" << endl;
  s1.insert(12);

  cout << "s1.count(5) returned ";
  cout << s1.count(5) << endl;    // 1

  cout << "s1.count(9) returned ";
  cout << s1.count(9) << endl;    // 0
} 

Program Output

s1.insert(5)
Inserted element: True
s1.insert(5)
Inserted element: False
s1.insert(8)
s1.insert(12)
s1.count(5) returned 1
s1.count(9) returned 0 

REFERENCES

Visual C++ Books Online: Visual C++ Books; C/C++; Standard C++ Library Reference

Additional query words: STL STLSample count string

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