Assignemnt #107 and Baby Calculator

Code

///Name: Ben Borglin
///Date: 1/5/16
///File name: BabyCalc.java
///Program Name: Baby Calculator
///period: 6

import java.util.Scanner;

public class BabyCalc
{
	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");
	}
}