set::find (STL Samples)

Illustrates how to use the set::find Standard Template Library (STL) function in Visual C++.

template<class _K, class _Pr, class _A>
   class set 
   {
      public:
      // Function 1:
      const_iterator find(const _K& _Kv) 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 find function is used to locate an element in a controlled sequence. It returns an iterator to the first element in the controlled sequence whose sort key matches its parameter. If no such element exists, the returned iterator equals end.

Example

// SetFind.cpp
// compile with: /EHsc
//
//      Illustrates how to use the find function to get an iterator
//      that points to the first element in the controlled sequence
//      that has a particular sort key.
//
// Functions:
//
//    find         Returns an iterator that points to the first element
//                 in the controlled sequence that has the same sort key
//                 as the value passed to the find function. If no such
//                 element exists, the iterator equals end().
//////////////////////////////////////////////////////////////////////

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

using namespace std ;

typedef set<int> SET_INT;

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

int main() {
  SET_INT s1;
  cout << "s1.insert(5)" << endl;
  s1.insert(5);
  cout << "s1.insert(8)" << endl;
  s1.insert(8);
  cout << "s1.insert(12)" << endl;
  s1.insert(12);

  SET_INT::iterator it;
  cout << "it=find(8)" << endl;
  it=s1.find(8);
  cout << "it!=s1.end() returned ";
  truefalse(it!=s1.end());  //  True

  cout << "it=find(6)" << endl;
  it=s1.find(6);
  cout << "it!=s1.end() returned ";
  truefalse(it!=s1.end());  // False
}

Output

s1.insert(5)
s1.insert(8)
s1.insert(12)
it=find(8)
it!=s1.end() returned True
it=find(6)
it!=s1.end() returned False

Requirements

Header: <set>

See Also

Concepts

Standard Template Library Samples