multimap::count() in C++ STL

The multimap::count is a built-in function in C++ STL which returns the number of times a key is present in the multimap container.

Syntax:

multimap_name.count(key)

Parameters: The function accepts one mandatory parameter key which specifies the key whose count in multimap container is to be returned.

Return Value: The function returns the number of times a key is present in the multimap container.

// C++ function for illustration
// multimap::count() function
#include <bits/stdc++.h>
using namespace std;

int main()
{

    // initialize container
    multimap<int, int> mp;

    // insert elements in random order
    mp.insert({ 2, 30 });
    mp.insert({ 1, 40 });
    mp.insert({ 2, 60 });
    mp.insert({ 2, 20 });
    mp.insert({ 1, 50 });
    mp.insert({ 4, 50 });

    // count the number of times
    // 1 is there in the multimap
    cout << "1 exists " << mp.count(1)
         << " times in the multimap\n";

    // count the number of times
    // 2 is there in the multimap
    cout << "2 exists " << mp.count(2)
         << " times in the multimap\n";

    return 0;
}

Output:

1 exists 2 times in the multimap
2 exists 3 times in the multimap