std::array<T,N>:: operator[]
Sequence | ||||
(C++11)
|
||||
(C++26)
|
||||
(C++11)
|
||||
Associative | ||||
Unordered associative | ||||
(C++11)
|
||||
(C++11)
|
||||
(C++11)
|
||||
(C++11)
|
||||
Adaptors | ||||
(C++23)
|
||||
(C++23)
|
||||
(C++23)
|
||||
(C++23)
|
||||
Views | ||||
(C++20)
|
||||
(C++23)
|
||||
Tables | ||||
Iterator invalidation | ||||
Member function table | ||||
Non-member function table |
Member types | |||||||||||||||||||||||||||||||||||||||||||||||
Member functions | |||||||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||||||||||
Non-member functions | |||||||||||||||||||||||||||||||||||||||||||||||
|
|
||||||||||||||||||||||||||||||||||||||||||||||
Helper classes | |||||||||||||||||||||||||||||||||||||||||||||||
Deduction guides (C++17) |
reference operator
[
]
(
size_type pos
)
;
|
(1) |
(since C++11)
(constexpr since C++17) |
const_reference operator
[
]
(
size_type pos
)
const
;
|
(2) |
(since C++11)
(constexpr since C++14) |
Returns a reference to the element at specified location pos . No bounds checking is performed.
Parameters
pos | - | position of the element to return |
Return value
Reference to the requested element.
Complexity
Constant.
Notes
Unlike std::map::operator[] , this operator never inserts a new element into the container. Accessing a nonexistent element through this operator is undefined behavior.
Example
The following code uses operator [ ] to read from and write to a std:: array < int , N > :
#include <array> #include <iostream> int main() { std::array<int, 4> numbers{2, 4, 6, 8}; std::cout << "Second element: " << numbers[1] << '\n'; numbers[0] = 5; std::cout << "All numbers:"; for (auto i : numbers) std::cout << ' ' << i; std::cout << '\n'; }
Output:
Second element: 4 All numbers: 5 4 6 8
See also
access specified element with bounds checking
(public member function) |