As discussed in the introduction, an array is used for collecting data of the same type together into one variable. In this section, we will discuss some of the cases where an array is an appropriate data structure to use.

Although arrays are essentially ordered lists of elements, it can still be appropriate to use an array to store data when the order of the data does not matter. Consider the example of a class of students where you need to store data about all of the students. If this were the problem you had to solve, you may create some data type that held all of the relevant information about any one particular student, such as name and average. Then you would use an array to store a student record for each student in the class. In a case like this, the index of each student is arbitrary; their position in the array means nothing. Instead you would be benefitting from the the fact that you can loop through the entire array and access the information about each of the students. This might be useful if you were interested in calculating class-wide statistics, such as what the average grade in the class was.

Similarly, you can also take advantage of the ordered nature of arrays. This is often used in cases where you needed to sort data. Reconsider the above class example. You may want to know the ranking of everyone in the class. Conveniently, all of the necessary information is already stored in the array. All you need to do is to apply one of the many sorting algorithms to the put the array into order by score.