std::deque::size

From cppreference.com
< cpplrm; | containerlrm; | deque

size_type size() const;
(until C++11)
size_type size() const noexcept;
(since C++11)

Returns the number of elements in the container, i.e. std::distance(begin(), end()).

Parameters

(none)

Return value

The number of elements in the container.

Complexity

Constant.

Example

The following code uses size to display the number of elements in a std::deque:

#include <deque>
#include <iostream>

int main()
{ 
    std::deque<int> nums {1, 3, 5, 7};

    std::cout << "nums contains " << nums.size() << " elements.\n";
}

Output:

nums contains 4 elements.

See also

checks whether the container is empty
(public member function)
returns the maximum possible number of elements
(public member function)
changes the number of elements stored
(public member function)