map::find
Returns an iterator addressing the location of an element in a map 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 value to be matched by the sort key of an element from the map being searched.
Return Value
An iterator that addresses the location of an element with a specified key, or the location succeeding the last element in the map if no match is found for the key.
Remarks
The member function returns an iterator that addresses an element in the map 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 map object cannot be modified. If the return value of find is assigned to an iterator, the map object can be modified
Example
// map_find.cpp
// compile with: /EHsc
#include <map>
#include <iostream>
int main( )
{
using namespace std;
map <int, int> m1;
map <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, 30 ) );
m1_RcIter = m1.find( 2 );
cout << "The element of map m1 with a key of 2 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 map m1 doesn't have an element "
<< "with a key of 4." << endl;
else
cout << "The element of map m1 with a key of 4 is: "
<< m1_RcIter -> second << "." << endl;
// The element at a specific location in the map 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 element of m1 with a key matching "
<< "that of the last element is: "
<< m1_RcIter -> second << "." << endl;
}
The element of map m1 with a key of 2 is: 20. The map m1 doesn't have an element with a key of 4. The element of m1 with a key matching that of the last element is: 30.
Requirements
Header: <map>
Namespace: std