Array Initialization

There are several ways to initialize a std::array in C++:

Default initialization

In this example, we create an array of 5 integers, with each element default-initialized. For int, this means they are initialized with a value of 0:

1std::array<int, 5> MyArray;

Initialization with specific values

This creates an array of 5 integers, with the elements initialized to the specified values:

1std::array<int, 5> MyArray{1, 2, 3, 4, 5};

Initialization with fewer values than the array size

Below, we provide initialisation for some of the values. The remaining elements will be value-initialized. For primitive types like int, this means they will be zero-initialized.

1std::array<int, 5> MyArray{1, 2, 3};

Initialization with class template argument deduction (CTAD)

In this example, the compiler deduces the type and size of the array based on the initializer list.

1std::array MyArray{1, 2, 3, 4, 5};

Default initialization with empty braces

In the following example, all elements will be value-initialized (zero-initialized in the case of int):

1std::array<int, 5> MyArray{};

Remember that std::array has a fixed size known at compile time, so you must specify the size when declaring the array, unless you use CTAD.