set::size (STL Sample)

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

Required Header:
<set>

template<class _K, class _Pr, class _A>
     class set 
     {
         public:
         // Function 1:
         size_type size() const;
     }

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

Description:
The size function is used to determine the number of elements in the controlled sequence.

Sample Code:

//////////////////////////////////////////////////////////////////////
//
// Compile options needed: -GX
//
// SetSize.cpp:
//      Illustrates how to use the size function to determine how
//      many elements are in the controlled sequence.
//
// Functions:
//
//    size         Returns the number of elements in the controlled
//                 sequence.
//
//////////////////////////////////////////////////////////////////////

#pragma warning(disable:4786)
#include <set>
#include <iostream>

using namespace std ;

typedef set<int> SET_INT;

void main() {
  SET_INT s1;

  cout << "s1.size() returned ";
  cout << s1.size() << endl;  // 0

  cout << "s1.insert(5)" << endl;
  s1.insert(5);
  cout << "s1.insert(8)" << endl;
  s1.insert(8);
  cout << "s1.insert(12)" << endl;
  s1.insert(12);

  cout << "s1.size() returned ";
  cout << s1.size() << endl; // 3
}

 

Program Output is:

s1.size() returned 0
s1.insert(5)
s1.insert(8)
s1.insert(12)
s1.size() returned 3