Question

create a new Java application called "Scorer" (without the quotation marks) that declares a two-dimensional array of doubles (call it scores) with three rows and three columns and that uses methods and loops as follows.

Use a method containing a nested while loop to get the nine (3 x 3) doubles from the user at the command line.

Use a method containing a nested for loop to compute the average of the doubles in each row.

Use a method to output these three row averages to the command line.

Note

The requirement is to use a two-dimensional array of type double called ‘scores’ with 3 rows and 3 columns.

Two methods are required.

The first method prompts the user to enter 9 values and then stores them in the scores array. Using a nested loop (for or while) is required. As long as you use a nested loop of some type, that’s fine.

The second method calculates the row averages. My approach was to store the row averages in a separate 3-element array (declared in main and passed into the method as a parameter along with the scores array). Use a nested for loop for processing the rows and calculating the row averages.

The third method takes the 3-element array containing the row averages and uses a for loop to display each of the average values.

Here is an example run:

run:

Enter 9 numbers

Value 1: 10

Value 2: 20

Value 3: 30

Value 4: 40

Value 5: 50

Value 6: 60

Value 7: 70

Value 8: 80

Value 9: 90

The average of row 1 is 20.00

The average of row 2 is 50.00

The average of row 3 is 80.00

Answer 1

Program:

import java.util.Scanner;

public class Scorer {

public static void main(String args[])

{

double scores[][] = new double[3][3];//scores array

getScores(scores);//method to get scores from user

double averages[] = new double[3];//to hold averages of user

getAverages(averages,scores);//method to calculate averages

printAverages(averages);//method to print averages

}

private static void printAverages(double[] averages) {

// TODO Auto-generated method stub

for(int i=0;i<3;i++)//iterating through array and printing averages

{

System.out.println("The average of row "+(i+1)+" is "+averages[i]);

}

}

private static void getAverages(double[] averages, double[][] scores) {

double sum=0;//to hold sum of each row

for(int i=0;i<3;i++)

{

for(int j=0;j<3;j++)

{

sum+=scores[i][j];

}

averages[i]=sum/3;//calculating and storing average

sum=0;

}

}

private static void getScores(double[][] scores) {

int i=0,j=0;

int count=1;

Scanner sc = new Scanner(System.in);//to read inout from user

System.out.println("Enter 9 numbers");

while(i<3)

{

j=0;

while(j<3)

{

System.out.println("value "+count);

scores[i][j]=sc.nextDouble();//reading into array

j++;

count++;

}

i++;

}

}

}

Output:

$Problems@ Javadoc Declaration terminated- Scorer [Java Application] C\Program Fil Enter 9 numbers value 1 10 value 2 20 value 3 30 value 4 40 value 5 50 value 6 60 value 7 70 value 8 80 value 9 90 The average of row 1 is 20.0 The average of row 2 is 50.0 The average of row 3 is 80.0$