Assignemnt #107 and Baby Calculator

Code

    ///Name: Daniel Tiffany-Appleton
    ///Period: 7
    ///Program Name: Baby Calculator
    ///File Name: BabyCalculator
    ///Date Finished: 3/14/16
    
    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("Bye now.");
                }
                else
                {
                    System.out.println(c);
                }
    
    		} while ( a !=0 );
    	}
    }

    

Picture of the output