We can implement a custom class that behaves like an array by creating a class that has an array as a private field, and implements the necessary methods to access and manipulate the array.

It’s important to note that creating custom array-like class like this one can be less efficient than using the built-in array class, since the built-in array class has been optimized for performance and memory usage. Additionally, since the Java standard library provides many classes like ArrayList, Vector, and LinkedList that are more powerful and flexible than a basic array class, it is recommended to use them instead of creating a custom array class like this example.

Advise: User ArrayList instead of Custom Array

Here’s an example of a simple custom array class called `CustomArray`:

public class CustomArray {
    private int[] array;
    private int size;

    // constructor
    public CustomArray(int size) {
        this.array = new int[size];
        this.size = size;
    }

    // get an element at a specific index
    public int get(int index) {
        if (index < 0 || index >= size) {
            throw new ArrayIndexOutOfBoundsException();
        }
        return array[index];
    }

    // set an element at a specific index
    public void set(int index, int value) {
        if (index < 0 || index >= size) {
            throw new ArrayIndexOutOfBoundsException();
        }
        array[index] = value;
    }

    // get the size of the array
    public int size() {
        return size;
    }
}

you can add more functionality such as resizing the array, or adding more methods like add, insert, remove,