Assignemnt Project #4 and Calculator

Code

    ///Name: Daniel Tiffany-Appleton
    ///Period: 7
    ///Program Name: Calculator
    ///File Name: Calculator
    ///Date Finished: 3/18/16
    
    import java.util.Scanner;
    
    public class Calculator
    {
        public static void main( String[] args ) 
        {
            Scanner keyboard = new Scanner(System.in);
            
            double intA, intB, answer;
            String op;
            
            System.out.println("");
            System.out.println("Calculator version 0.12 (c) 2015 TA Inc." );
            
            
            do
            {
                System.out.print("> ");
                intA = keyboard.nextDouble();
                op = keyboard.next();
                
                if( intA==0 )
                {
                    System.out.println("Bye now.");
                    return;
                }
                
                if(op.equals("!"))
                {
                    answer = Factorials(intA);
                    System.out.println(answer);
                    continue;
                }
                
                intB = keyboard.nextDouble();
                answer = 1;
                
                
                if( op.equals("+"))
                {
                    answer = intA + intB;
                    System.out.println(answer);
                }
                
                else if( op.equals("-"))
                {
                    answer = intA - intB;
                    System.out.println(answer);
                }
                
                else if( op.equals("*"))
                {
                    answer = intA * intB;
                    System.out.println(answer);
                }
                
                else if( op.equals("/"))
                {
                    answer = intA / intB;
                    System.out.println(answer);
                }
                
                else if( op.equals("^"))
                {
                    answer = Power(intA,intB);
                    System.out.println(answer);
                }
                
                else if( op.equals("%"))
                {
                    answer = intA % intB;
                    System.out.println(answer);
                }
                
                else
                {
                    System.out.println("ERROR! UNRECOGNIZED OPERATION!");
                }
                
            }while(intA != 0);
        }
        
        public static double Power(double intA, double intB)
        {
            double answer, power;
            answer = 1;
            power = 0;
            
            while(power != intB)
            {
                answer = intA * answer;
                power++;
            }
            
            return answer;
        }
        
        public static double Factorials(double intA)
        {
            double answer, n, x;
            answer = 1;
            x = 1;
            
            for(n = 1; n <= intA; n++)
            {
                answer = x * n;
                x = answer;
            }
            
            return answer;
        }
            
    }

    

Picture of the output