std::unordered_map<Key,T,Hash,KeyEqual,Allocator>::size
From cppreference.com
< cpp | container | unordered map
size_type size() const noexcept; |
(since C++11) | |
Returns the number of elements in the container, i.e. std::distance(begin(), end()).
Contents |
[edit] Parameters
(none)
[edit] Return value
The number of elements in the container.
[edit] Complexity
Constant.
[edit] Example
The following code uses size
to display the number of elements in a std::unordered_map
:
Run this code
#include <iostream> #include <unordered_map> int main() { std::unordered_map<int,char> nums{{1, 'a'}, {3, 'b'}, {5, 'c'}, {7, 'd'}}; std::cout << "nums contains " << nums.size() << " elements.\n"; }
Output:
nums contains 4 elements.
[edit] See also
checks whether the container is empty (public member function) | |
returns the maximum possible number of elements (public member function) | |
(C++17)(C++20) |
returns the size of a container or array (function template) |