Chapter 15, Problem 1E

Explanation of Solution

Adding the “lastIndexOf” methods in “ArrayIntList” class:

//definition of "ArrayIntList" class

public class ArrayIntList

{

    //declare the required variables

    private int[] elementData;

    private int size;

    //refer the remaining methods in the textbook

    //definition of "lastIndexOf" method

    public int lastIndexOf(int value)

    {

/*iterate "i" until it reaches the size of an array*/

        for (int i = size - 1; i >= 0; i--)

        {

            //check the condition

            if (elementData[i] == value)

            {

                //return the "i" value

                return i;

            }

        }

        //return the value

        return -1;

    }

}

Explanation:

In the above program, the “ArrayIntList” is the class name,

• Inside the “ArrayIntList” class, declare the “elementData”, and “size” variables as a private integer datatype.
  • The “lastIndexOf” method is defined inside the “ArrayIntList” class with the integer value as the parameter.
    • The “for” loop is used to iterate the value until it reaches size of an array.
      • The “if” loop is used to check whether the array of element value is equal to passed value.
        • The “i^th” position of an array value is returned.
    • If the value is not in an array return the -1 value.