C++ .bucket()

The .bucket() function is part of the C++ unordered_map container. It returns the bucket number (zero-indexed) where a specified element is located within the unordered map. Each element in the unordered map is assigned to a bucket based on its hash value, and this function helps determine which bucket a given key belongs to.

Syntax

size_type bucket(const key_type& k) const;

• key: The key whose bucket number needs to be found in the unordered map.

The function returns a size_type value, representing the zero-indexed bucket number where the specified key is stored.

Example

In this example, the bucket() function is used to find the bucket number for the key "banana" in the unordered map:

#include <iostream>
#include <unordered_map>

int main() {
    std::unordered_map<std::string, int> umap;
    umap["apple"] = 1;
    umap["banana"] = 2;
    umap["cherry"] = 3;

    std::string key = "banana";
    std::cout << "The bucket for key '" << key << "' is: " << umap.bucket(key) << std::endl;

    return 0;
}

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The above code generates the following output:

The bucket for key 'banana' is: 4

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Codebyte Example

In this Codebyte, we are using the bucket() function to find the bucket for the key "cherry" in the unordered map:

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