Arrays

An array groups several values of the same type together under one name, stored contiguously in memory (right next to each other). You declare one with type name[size]; (for example int nums[3]; makes room for exactly three ints) and you can provide initial values right away with curly braces, like int nums[3] = {3, 1, 2};.

Elements are accessed with square brackets and a zero-based index: nums[0] is the first element, nums[1] is the second, nums[2] is the third (and last, in a 3-element array). Reading or writing nums[3] on this array would reach one slot past the end. C does not stop you from doing this, and it's one of the most notorious sources of bugs and security vulnerabilities in real C programs, so always double-check your bounds.