multimap::find
Returns an iterator addressing the first location of an element in a multimap that has a key equivalent to a specified key.
iterator find(
const Key& _Key
);
const_iterator find(
const Key& _Key
) const;
Parameters
- _Key
The key to be matched by the sort key of an element from the multimap being searched.
Return Value
An iterator that addresses the first location of an element with a specified key, or the location succeeding the last element in the multimap if no match is found for the key.
Remarks
The member function returns an iterator that addresses an element in the multimap whose sort key is equivalent to the argument key under a binary predicate that induces an ordering based on a less than comparability relation.
If the return value of find is assigned to a const_iterator, the multimap object cannot be modified. If the return value of find is assigned to an iterator, the multimap object can be modified.
Example
// multimap_find.cpp
// compile with: /EHsc
#include <map>
#include <iostream>
int main( )
{
using namespace std;
multimap <int, int> m1;
multimap <int, int> :: const_iterator m1_AcIter, m1_RcIter;
typedef pair <int, int> Int_Pair;
m1.insert ( Int_Pair ( 1, 10 ) );
m1.insert ( Int_Pair ( 2, 20 ) );
m1.insert ( Int_Pair ( 3, 20 ) );
m1.insert ( Int_Pair ( 3, 30 ) );
m1_RcIter = m1.find( 2 );
cout << "The element of multimap m1 with a key of 2 is: "
<< m1_RcIter -> second << "." << endl;
m1_RcIter = m1.find( 3 );
cout << "The first element of multimap m1 with a key of 3 is: "
<< m1_RcIter -> second << "." << endl;
// If no match is found for the key, end( ) is returned
m1_RcIter = m1.find( 4 );
if ( m1_RcIter == m1.end( ) )
cout << "The multimap m1 doesn't have an element "
<< "with a key of 4." << endl;
else
cout << "The element of multimap m1 with a key of 4 is: "
<< m1_RcIter -> second << "." << endl;
// The element at a specific location in the multimap can be
// found using a dereferenced iterator addressing the location
m1_AcIter = m1.end( );
m1_AcIter--;
m1_RcIter = m1.find( m1_AcIter -> first );
cout << "The first element of m1 with a key matching"
<< endl << "that of the last element is: "
<< m1_RcIter -> second << "." << endl;
// Note that the first element with a key equal to
// the key of the last element is not the last element
if ( m1_RcIter == --m1.end( ) )
cout << "This is the last element of multimap m1."
<< endl;
else
cout << "This is not the last element of multimap m1."
<< endl;
}
The element of multimap m1 with a key of 2 is: 20.
The first element of multimap m1 with a key of 3 is: 20.
The multimap m1 doesn't have an element with a key of 4.
The first element of m1 with a key matching
that of the last element is: 20.
This is not the last element of multimap m1.
Requirements
Header: <map>
Namespace: std