iterator begin ();
const_iterator begin () const;
Return iterator to beginning
Returns an iterator referring to the first element in the container.
Internally, multimap containers keep their elements ordered by their keys from lower to higher , therefore begin returns an element with the lowest key value in the container.
Parameters
none
Return Value
An iterator to the first element in the container.
Both iterator and const_iterator are member types. In the multimap class template, these are bidirectional iterators.
Dereferencing this iterator accesses the element's value, which is of type pair<const Key,T>.
Example
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// multimap::begin/end
#include <iostream>
#include <map>
using namespace std;
int main ()
{
multimap<char,int> mymultimap;
multimap<char,int>::iterator it;
mymultimap.insert (pair<char,int>('a',10));
mymultimap.insert (pair<char,int>('b',20));
mymultimap.insert (pair<char,int>('b',150));
// show content:
for ( it=mymultimap.begin() ; it != mymultimap.end(); it++ )
cout << (*it).first << " => " << (*it).second << endl;
return 0;
}
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Output:
Complexity
Constant.
See also
| multimap::rbegin | Return reverse iterator to reverse beginning (public member function) |
| multimap::rend | Return reverse iterator to reverse end (public member function) |
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