std::array<T,N>::data

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros(C++20)

Language support library

Concepts library(C++20)

Diagnostics library

Memory management library

Metaprogramming library(C++11)

General utilities library

Containers library

Iterators library

Ranges library(C++20)

Algorithms library

Strings library

Text processing library

Numerics library

Date and time library

Input/output library

Filesystem library(C++17)

Concurrency support library(C++11)

Execution control library(C++26)

Technical specifications

Symbols index

External libraries

 

Containers library

node-handle (C++17)

Sequence

array (C++11)

vector

vector<bool>

inplace_vector (C++26)

hive (C++26)

deque

forward_list (C++11)

list

Associative

set

multiset

map

multimap

Unordered associative

unordered_set (C++11)

unordered_multiset (C++11)

unordered_map (C++11)

unordered_multimap (C++11)

Adaptors

stack

queue

priority_queue

flat_set (C++23)

flat_multiset (C++23)

flat_map (C++23)

flat_multimap (C++23)

Views

span (C++20)

mdspan (C++23)

Tables

Iterator invalidation

Member function table

Non-member function table

 

std::array

Member types
Member functions
Element access array::at array::operator[]    array::front array::back array::data Operations array::fill array::swap	Iterators array::beginarray::cbegin array::endarray::cend array::rbeginarray::crbegin    array::rendarray::crend	Capacity array::empty array::size array::max_size
Non-member functions
operator==operator<=> (C++20) get(std::array) swap(std::array) to_array (C++20)	operator|=operator<operator>operator<=operator>= (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)
Helper classes
tuple_size<std::array>
tuple_element<std::array>
Deduction guides(C++17)

 

T* data()noexcept;	(1)	(since C++11) (constexpr since C++17)
const T* data()constnoexcept;	(2)	(since C++11) (constexpr since C++17)

Returns a pointer to the underlying array serving as element storage. The pointer is such that range [data(), data()+ size()) is always a valid range, even if the container is empty (data() is not dereferenceable in that case).

Parameters

(none)

Return value

Pointer to the underlying element storage. For non-empty containers, the returned pointer compares equal to the address of the first element.

Complexity

Constant.

Notes

If size() is ​0​, data() may or may not return a null pointer.

Example

Run this code

#include <cstddef>#include <iostream>#include <span>#include <array>   void pointer_func(constint* p, std::size_t size){std::cout<<"data = ";for(std::size_t i =0; i < size;++i)std::cout<< p[i]<<' ';std::cout<<'\n';}   void span_func(std::span<constint> data)// since C++20{std::cout<<"data = ";for(constint e : data)std::cout<< e <<' ';std::cout<<'\n';}   int main(){std::array<int, 4> container{1, 2, 3, 4};   // Prefer container.data() over &container[0] pointer_func(container.data(), container.size());   // std::span is a safer alternative to separated pointer/size. span_func({container.data(), container.size()});}

Output:

data = 1 2 3 4 data = 1 2 3 4

See also

front	access the first element (public member function)
back	access the last element (public member function)
size	returns the number of elements (public member function)
operator[]	access specified element (public member function)
span (C++20)	a non-owning view over a contiguous sequence of objects (class template)
data (C++17)	obtains the pointer to the underlying array (function template)