# std::unordered_map<Key,T,Hash,KeyEqual,Allocator>::end, std::unordered_map<Key,T,Hash,KeyEqual,Allocator>::cend

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< cpp‎ | container‎ | unordered map

iterator end() noexcept; | (1) | (since C++11)
const_iterator end() const noexcept; | (2) | (since C++11)
const_iterator cend() const noexcept; | (3) | (since C++11)

Returns an iterator to the element following the last element of the `unordered_map`.

This element acts as a placeholder; attempting to access it results in undefined behavior.

### Parameters

(none)

### Return value

Iterator to the element following the last element.

### Complexity

Constant.

### Example

Run this code

    #include <cmath>
    #include <iostream>
    #include <unordered_map>

    struct Node { double x, y; };

    int main()
    {
        Node nodes[3] = {{1, 0}, {2, 0}, {3, 0}};

        // mag is a map mapping the address of a Node to its magnitude in the plane
        std::unordered_map<Node*, double> mag =
        {
            { nodes + 0, 1 },
            { nodes + 1, 2 },
            { nodes + 2, 3 }
        };

        // Change each y-coordinate from 0 to the magnitude
        for (auto iter = mag.begin(); iter != mag.end(); ++iter)
        {
            auto cur = iter->first; // pointer to Node
            cur->y = mag[cur]; // could also have used cur->y = iter->second;
        }

        // Update and print the magnitude of each node
        for (auto iter = mag.begin(); iter != mag.end(); ++iter)
        {
            auto cur = iter->first;
            mag[cur] = std::hypot(cur->x, cur->y);
            std::cout << "The magnitude of (" << cur->x << ", " << cur->y << ") is ";
            std::cout << iter->second << '\n';
        }

        // Repeat the above with the range-based for loop
        for (auto i : mag)
        {
            auto cur = i.first;
            cur->y = i.second;
            mag[cur] = std::hypot(cur->x, cur->y);
            std::cout << "The magnitude of (" << cur->x << ", " << cur->y << ") is ";
            std::cout << mag[cur] << '\n';
            // Note that in contrast to std::cout << iter->second << '\n'; above,
            // std::cout << i.second << '\n'; will NOT print the updated magnitude
        }
    }

Possible output:

    The magnitude of (3, 3) is 4.24264
    The magnitude of (1, 1) is 1.41421
    The magnitude of (2, 2) is 2.82843
    The magnitude of (3, 4.24264) is 5.19615
    The magnitude of (1, 1.41421) is 1.73205
    The magnitude of (2, 2.82843) is 3.4641

### See also

begincbegin | returns an iterator to the beginning (public member function)
endcend (C++11)(C++14) | returns an iterator to the end of a container or array (function template)

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