Assignment #73 and Baby Calculator

Code

    /// Name: Ali Kurland
    /// Period: 6
    /// Program Name: Baby Calculator
    /// File Name: BabyCalculator.java
    /// Date Finished: 10/19/2015
    
    import java.util.Scanner;
    
    public class BabyCalculator
    {
      public static void main( String[] args )
      {
        Scanner keyboard = new Scanner(System.in);
    
        double a, b, c;
        String op;
    
        do
        {
          System.out.print("> ");
          a  = keyboard.nextDouble();
          op = keyboard.next();
          b  = keyboard.nextDouble();
    
          if ( op.equals("+") )
            c = a + b;
          else if ( op.equals("-") )
            c = a - b;
          else if ( op.equals("*") )
            c = a * b;
          else if ( op.equals("/") )
            c = a / b;
          else
          {
            System.out.println("Undefined operator: '" + op + "'.");
            c = 0;
          }
          if ( a != 0 )
          {
    			System.out.println(c);
          }
        } while ( a != 0 );
            
            System.out.println( "Bye, now." );
      }
    }
    

Picture of the output