Array
An array is a data structure that stores a set of elements of the same type in a specific, continuous order. Each element has its own unique number — an index.
In simpler terms, it is a numbered sequence of cells, where each cell holds a value.
What is an index
An index is the position number of an element in an array. It shows exactly where in the array a specific value is located.
You can think of an index as the address of a cell that you can use to find or change an element.
In C#, indexes start at zero.
If you access an index that does not exist — the program will throw an error (IndexOutOfRangeException).
A real-life analogy
In real life, you can find arrays everywhere, for example, a row of seats in a movie theater:
- The entire row of seats is an array.
- Each seat is a cell of the array.
- A viewer is the value of an array cell.
- The seat number is the index. The only difference is that in arrays the index starts at 0. If you want to know who is sitting in the 3rd seat — you access index [2].
Array operations:
- creation
- reading by index
- writing by index, adding, deleting
- iteration, searching
- sorting
These operations will be covered in detail throughout the course.