unordered_multimap swap() function in C++ STL

unordered_multimap swap() function in C++ STL is used to swap the elements of one multimap to another of same size and type.

Algorithm

Begin
   Declaring two empty map container m, m1.
   Insert some values in both m, m1 map containers.
   Perform swap() function to swap the values of m, m1 map containers.
   Printing the swapped values of m map container.
   Printing the swapped values of m1 map container.
End.

Example Code

 Live Demo

#include<iostream>
#include <bits/stdc++.h>
using namespace std;

int main() {
   unordered_map<char, int> m,m1; // declaring m, m1 as empty map container

   m.insert (pair<char, int>('b', 10)); //inserting values in map container
   m.insert (pair<char, int>('c',30));
   m.insert (pair<char, int>('d',40));
   m1.insert (pair<char, int>('a', 20));
   m1.insert (pair<char, int>('e',70));
   m1.insert (pair<char, int>('f',60));
   m.swap(m1); // swapping the values of two map container.

   cout << "\n Key and values of 1st set are:";
   for (auto it = m.begin(); it != m.end(); it++) {
      cout << "{" << it->first << ", " << it->second << "} "; // printing the swapped values of m map container
   }

   cout << "\n Key and values of 2nd set are:"; // printing the swapped values of m1 map container
   for (auto it = m1.begin(); it != m1.end(); it++) {
      cout << "{" << it->first << ", " << it->second << "} ";
   }
   return 0;
}

Output

Key and values of 1st set are: {f, 60} {a, 20} {e, 70}
Key and values of 2nd set are: {d, 40} {b, 10} {c, 30}.