Question

blueJ code given:

import java.until.ArrayList;

public class TestArrayList;

{

private ArrayList<TestArrays> testArrayList;

/**

* Complete the constructor for the class. Instantiate the testArrayList

*and call the fillArrayList method to add objects to the testArrayList.

* @param numElements The number of elements in the ArrayList

*/

public TestArrayLists(int numElements)

{

}

/**

* Complete the fillArrayList method. It should fill the testArrayList with

* TestArrays objects consisting of 10 element int Array of random numbers.

* @param numElements The number of elements in the ArrayList

*/

private void fillArrayList(int numElements)

{

}

/**

* For each TestArrays object in the testArrayList,

*print out the numbers in the int Array.

*/

public void printArrayList()

{

}

}

Answer 1

Below are the 2 classes you will be needing, I have kept the main() method inside the TestArrayList.java class, you can run this class and see the output.


===========================================================================


import java.util.Random;

public class TestArrays {

    private int[] numbers;

    public TestArrays(int size) {

        numbers = new int[size];
        Random random = new Random();

        for (int i = 0; i < size; i++) numbers[i] = random.nextInt(100) + 1;
    }

    public void display() {

        for (int i = 0; i < numbers.length; i++) {
            System.out.printf("%5d", numbers[i]);
        }
        System.out.println();
    }
}

================================================================

import java.util.ArrayList;

public class TestArrayList {

    private ArrayList<TestArrays> testArrayList;

    /**
     * Complete the constructor for the class. Instantiate the testArrayList
     * <p>
     * and call the fillArrayList method to add objects to the testArrayList.
     *
     * @param numElements The number of elements in the ArrayList
     */

    public TestArrayList(int numElements) {
        testArrayList = new ArrayList<>();
        fillArrayList(numElements);
    }

    /**
     * Complete the fillArrayList method. It should fill the testArrayList with
     * TestArrays objects consisting of 10 element int Array of random numbers.
     *
     * @param numElements The number of elements in the ArrayList
     */

    private void fillArrayList(int numElements) {

        for (int i = 0; i < 10; i++) {
            testArrayList.add(new TestArrays(numElements));
        }

    }

    /**
     * For each TestArrays object in the testArrayList,
     * print out the numbers in the int Array.
     */

    public void printArrayList() {

        for (TestArrays testArrays : testArrayList) {
            testArrays.display();
            ;
        }

    }


    public static void main(String[] args) {

        TestArrayList list = new TestArrayList(10);
        list.printArrayList();
    }

}

================================================================