Explore the full potential of C++ by mastering the standard library.

Become a C++ Programmer

The C++ standard library is a collection of all the tools and utilities available in C++. It received its latest update in 2017, known as C++17. The update introduces many new features that further optimize our code. This module will help us fully grasp C++ and use it to its full potential.

C++ Standard Library

[std::array](http://en.cppreference.com/w/cpp/container/array) is a homogeneous container of fixed length. It requires the header `<array>`. An instance of `std::array` combines the memory and runtime characteristic of a C array with the interface of an `std::vector`.In particular, an `std::array` knows its size. We can use STL algorithms on instances of `std::array`.

Keep a few special rules in mind for initializing an `std::array`.

- `std::array<int, 10> arr`: The 10 elements are not initialized.

- `std::array<int, 10> arr{}`: The 10 elements initialized to 0 by default.

- `std::array<int, 10> arr{1, 2, 3, 4, 5}`: The unspecified elements are initialized to 0 by default.

`std::array` supports three types of index access. 

```C++
- arr[n];
- arr.at(n);
- std::get<n>(arr);
```

The most commonly used first type of index access using angle brackets does not check the boundaries of the `arr`. This is in contrast to `arr.at(n)`. We will eventually get an `std::range-error` exception. The last form in the above snippet shows the relationship of `std::array` with the [std::tuple](https://www.educative.io/courses/cpp-fundamentals-for-professionals/std-tuple), because both are containers of fixed length.

Here is a little bit of arithmetic using `std::array`:

The array type is perhaps the most popular sequential container. This lesson will cover its properties in detail.

Arrays