What is the advantage of declaring an array size using a constant

Question

What is the advantage of declaring an array using a constant in Java? For example,

private static final int CAPACITY = 2;
private int[] items = new int[CAPACITY];

What is difference between the above code and:

private int[] items = new int[2];

Note: An array's length cannot be changed once it is declared. Why should I use constant then?

Answer 1

Because if the CAPACITY is used somewhere else, and in the future you decide that the CAPACITY should be 4, you don't need to change it everywhere.

• improves readability of the code
• easier to maintain

Compare:

for(int i=0;i<2;i++) 

to

for(int i=0;i<CAPACITY;i++)

Avoid magic numbers in the code when you can.

Many Java classes uses constants, Integer, Character and more classes.

Answer 2

1. you can use this constant for some other array
2. to make clear of why is this length like: STUDENTS_MAX_SIZE = 1000