Arrays

Array are a one dimensional data structure. You can think of an array as a long list of data. Generally arrays are static, meaning they do not change in size. Another property that is typical an array is that each element is the same type/size.

Reading From An Array

To read from an array, you use an index. The index refers to the element number that you want to look at. Index values start at 0, so if you want to view the first element of an array you would check the value at index 0. The reason for this is that arrays fit in memory linearly. The index is the offset in memory from the first value. This property makes it extremely fast to randomly access any element in the array, which is why arrays are awesome!

Writing To An Array

You are able to write anywhere in an array using the index. You specify an element that you want to write to, and then store a value there. Array elements can be written in any order, but it is usually best to try and keep your data tightly packed. If you want to add an element to an array it can be helpful to maintain a count that tells you how many values are in the array so you can write to the end. Because arrays do not change size, be careful not to add more elements to the array than the array has space for.

Deleting From An Array

When you delete from an array it can be from anywhere, not just the end. Usually if you delete from the beginning or the end it will leave a hole that you will want to fill up. You can either keep track of your holes, or you can shift all the elements over to remove the holes. This can take a lot of time if deleting is a common operation, so keep that in mind. With that being said, arrays are such an efficient structure that even having thousands of shifts is often still faster than having a linked list.