# std::array<T,N>::begin, std::array<T,N>::cbegin

From cppreference.com
< cpp‎ | container‎ | array

iterator begin() noexcept; | (1) | (since C++11) (constexpr since C++17)
const_iterator begin() const noexcept; | (2) | (since C++11) (constexpr since C++17)
const_iterator cbegin() const noexcept; | (3) | (since C++11) (constexpr since C++17)

Returns an iterator to the first element of the `array`.

If the `array` is empty, the returned iterator will be equal to end().

### Parameters

(none)

### Return value

Iterator to the first element.

### Complexity

Constant.

### Example

Run this code

    #include <algorithm>
    #include <array>
    #include <iomanip>
    #include <iostream>

    int main()
    {
        std::cout << std::boolalpha;

        std::array<int, 0> empty;
        std::cout << "1) "
                  << (empty.begin() == empty.end()) << ' '     // true
                  << (empty.cbegin() == empty.cend()) << '\n'; // true
        // *(empty.begin()) = 42; // => undefined behavior at run-time

        std::array<int, 4> numbers{5, 2, 3, 4};
        std::cout << "2) "
                  << (numbers.begin() == numbers.end()) << ' '    // false
                  << (numbers.cbegin() == numbers.cend()) << '\n' // false
                  << "3) "
                  << *(numbers.begin()) << ' '    // 5
                  << *(numbers.cbegin()) << '\n'; // 5

        *numbers.begin() = 1;
        std::cout << "4) " << *(numbers.begin()) << '\n'; // 1
        // *(numbers.cbegin()) = 42; // compile-time error:
                                     // read-only variable is not assignable

        // print out all elements
        std::cout << "5) ";
        std::for_each(numbers.cbegin(), numbers.cend(), [](int x)
        {
            std::cout << x << ' ';
        });
        std::cout << '\n';

        constexpr std::array constants{'A', 'B', 'C'};
        static_assert(constants.begin() != constants.end());   // OK
        static_assert(constants.cbegin() != constants.cend()); // OK
        static_assert(*constants.begin() == 'A');              // OK
        static_assert(*constants.cbegin() == 'A');             // OK
        // *constants.begin() = 'Z'; // compile-time error:
                                     // read-only variable is not assignable
    }

Output:

    1) true true
    2) false false
    3) 5 5
    4) 1
    5) 1 2 3 4

### See also

endcend | returns an iterator to the end (public member function)
begincbegin (C++11)(C++14) | returns an iterator to the beginning of a container or array (function template)

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