Assignemnt #73 and baby Calculator

Code

    
    ///name: nick cerdan
    ///period: 6
    ///progrram name: Baby calculator
    ///file name: BabyCalculator.java
    ///date finished: 10/26/15
    
    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;
    			}
    
    			System.out.println(c);
    
    		} while (a != 0);
            System.out.println("Bye, now.");
    	}
    }
    
    Assignment 72