std::array::empty

From cppreference.com

< cpp‎ | container‎ | array

constexpr bool empty();		(since C++11) (until C++14)
constexpr bool empty() const;		(since C++14)

Checks if the container has no elements, i.e. whether begin() == end().

Contents

[edit] Parameters

(none)

[edit] Return value

true if the container is empty, false otherwise

[edit] Exceptions

noexcept specification:

noexcept

[edit] Complexity

Constant.

[edit] 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

size	returns the number of elements (public member function)

Retrieved from "http://en.cppreference.com/mwiki/index.php?title=cpp/container/array/empty&oldid=50436"

unconditionally noexcept