std::array::size

C++

Language

Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

Containers library

array (C++11)

vector

deque

forward_list (C++11)

list

set

multiset

map

multimap

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

stack

queue

priority_queue

span (C++20)

std::array

Member functions

Element access

array::at

array::operator[]

array::front

array::back

array::data

Iterators

array::beginarray::cbegin

array::endarray::cend

array::rbeginarray::crbegin

array::rendarray::crend

Capacity

array::empty

array::size

array::max_size

Modifiers

array::fill

array::swap

Non-member functions

get

swap

operator==operator!=operator<operator>operator<=operator>=

Helper classes

tuple_size

tuple_element

Deduction guides(C++17)

constexpr 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::array:

Run this code

#include <array>
#include <iostream>

int main()
{ 
    std::array<int, 4> nums {1, 3, 5, 7};

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

Output:

nums contains 4 elements.

See also

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