Average.java

Below is the syntax highlighted version of Average.java from §1.1 Programming Model.

/******************************************************************************
 *  Compilation:  javac Average.java
 *  Execution:    java Average < data.txt
 *  Dependencies: StdIn.java StdOut.java
 *
 *  Reads in a sequence of real numbers, and computes their average.
 *
 *  % java Average
 *  10.0 5.0 6.0
 *  3.0 7.0 32.0
 *  [Ctrl-d]
 *  Average is 10.5
 *
 *  Note [Ctrl-d] signifies the end of file on Unix.
 *  On windows use [Ctrl-z].
 *
 ******************************************************************************/

/**
 *  The {@code Average} class provides a client for reading in a sequence
 *  of real numbers and printing out their average.
 *  <p>
 *  For additional documentation, see <a href="https://algs4.cs.princeton.edu/11model">Section 1.1</a> of
 *  <i>Algorithms, 4th Edition</i> by Robert Sedgewick and Kevin Wayne.
 *
 *  @author Robert Sedgewick
 *  @author Kevin Wayne
 */
public class Average {

    // this class should not be instantiated
    private Average() { }

    /**
     * Reads in a sequence of real numbers from standard input and prints
     * out their average to standard output.
     *
     * @param args the command-line arguments
     */
    public static void main(String[] args) {
        int count = 0;       // number input values
        double sum = 0.0;    // sum of input values

        // read data and compute statistics
        while (!StdIn.isEmpty()) {
            double value = StdIn.readDouble();
            sum += value;
            count++;
        }

        // compute the average
        double average = sum / count;

        // print results
        StdOut.println("Average is " + average);
    }
}