set::size (STL Samples)
Illustrates how to use the set::size Standard Template Library (STL) function in Visual C++.
template<class _K, class _Pr, class _A>
class set
{
public:
// Function 1:
size_type size() const;
}
Remarks
注意
The class/parameter names in the prototype do not match the version in the header file. Some have been modified to improve readability.
The size function is used to determine the number of elements in the controlled sequence.
Example
// SetSize.cpp
// compile with: /EHsc
//
// 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;
int 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
}
Output
s1.size() returned 0 s1.insert(5) s1.insert(8) s1.insert(12) s1.size() returned 3
Requirements
Header: <set>