std::array::empty
From cppreference.com
| constexpr bool empty() const noexcept; |
(since C++11) (until C++20) |
|
| [[nodiscard]] constexpr bool empty() const noexcept; |
(since C++20) | |
Checks if the container has no elements, i.e. whether begin() == end().
Parameters
(none)
Return value
true if the container is empty, false otherwise
Complexity
Constant.
Example
The following code uses empty to check if a std::array contains any elements:
Run this code
#include <array> #include <iostream> int main() { std::array<int, 4> numbers {3, 1, 4, 1}; std::array<int, 0> no_numbers; std::cout << "numbers.empty(): " << numbers.empty() << '\n'; std::cout << "no_numbers.empty(): " << no_numbers.empty() << '\n'; }
Output:
numbers.empty(): 0 no_numbers.empty(): 1
See also
| returns the number of elements (public member function) |