unordered_map bucket() in C++ STL (original) (raw)

Last Updated : 11 Jun, 2021

The unordered_map::bucket() is a built-in STL function in C++ which returns the bucket number where the element with the key k is located in the map.
Syntax:

size_type bucket(key)

Parameter: The function accepts one mandatory parameter key which specifies the key whose bucket number is to be returned.
Return Value: This method returns an unsigned integral type which represents the bucket number of the key k which is passed in the parameter.
Below program illustrate the unordered_map::bucket() function:

CPP `

// CPP program to demonstrate the // unordered_map::bucket() function #include <bits/stdc++.h> using namespace std;

int main() { // Declaration unordered_map<string, string> mymap;

// Initialisation
mymap = { { "Australia", "Canberra" },
          { "U.S.", "Washington" },
          { "France", "Paris" } };

// prints the bucket number of the beginning element
auto it = mymap.begin();

// stores the bucket number of the key k
int number = mymap.bucket(it->first);
cout << "The bucket number of key " << it->first 
                                 << " is " << number;

return 0;

}

`

Output:

The bucket number of key France is 3