The near-complete program is given below.
The following program computes the average for group "A".
The average is computed using double precision floating point,
even though the two quantities involved are both of type int
.
To do this,
a type cast is used to convert sumA
into a double
so
that the division is floating point division, not integer division.
import java.io.*; import java.util.Scanner; class TestGroups { public static void main ( String[] args ) throws IOException { int value; // the value of the current integer // Prompt for and open the input file Scanner user = new Scanner( System.in ); System.out.print("File name? "); String fileName = user.next().trim(); Scanner scan = new Scanner( new File(fileName) ); // Group "A" int sizeA; // the number of students in group "A" int sumA = 0; // the sum of scores for group "A" sizeA = scan.nextInt(); int count = 0; // initialize count while ( count < sizeA ) { value = scan.nextInt(); sumA = sumA + value ; // add to the sum count = count + 1; // increment the count } if ( sizeA > 0 ) System.out.println( "Group A average: " + ((double) sumA)/sizeA ); else System.out.println( "Group A has no students" ); // Group "B" . . . . more code will go here . . . . } }
If you were writing this program on your own, what would be a nice thing to do at this point?