# Project #4 and Calculator

## Code

```/// Name: Raff Lisbona
/// Period: 6
/// Program Name: Project Calculator
/// File Name: ProjectCalculator.java
/// Date Finished: 4/11/2016

import java.util.Scanner;

public class ProjectCalculator
{
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("+") )
else if ( op.equals("-") )
c = subtract(a, b);
else if ( op.equals("*") )
c = multiply(a, b);
else if ( op.equals("/") )
c = divide(a, b);
else if ( op.equals("!") )
c = factorial(a);
else if ( op.equals("%") )
c = modulus(a, b);
else if ( op.equals("^") )
c = exponent(a, b);
else
{
System.out.println("Undefined operator: '" + op + "'.");
c = 0;
}

System.out.println(c);

} while ( a != 0 );
System.out.println("Bye, now.");
}

public static double add( double a, double b )
{
double total;
total = a + b;
}
public static double subtract( double a, double b)
{
double total;
total = a - b;
}
public static double multiply( double a, double b)
{
double total;
total = a * b;
}
public static double divide( double a, double b)
{
double total;
total = a / b;
}
public static double factorial( double a)
{
double total = a;
double z = a - 1;
for ( double x = z; x > 0; x-- )
total = total * x;
}
public static double modulus( double a, double b)
{
double total;
total = a % b;