I did it without using GUI because i am not sure how to do in GUI.I need help to put these code in GUI.
import java.util.Scanner;
import java.util.Stack;
/**
This calculator uses the reverse polish notation.
*/
public class Calculator
{
public static void main(String[] args)
{
Scanner in = new Scanner(System.in);
Stack<Integer> results = new Stack<Integer>();
System.out.println("Enter one number or operator per line, Q to quit. ");
boolean done = false;
while (!done)
{
String input = in.nextLine();
// If the command is an operator, pop the arguments and push the result
if (input.equals("+"))
{
results.push(results.pop() + results.pop());
}
else if (input.equals("-"))
{
Integer arg2 = results.pop();
results.push(results.pop() - arg2);
}
else if (input.equals("*") || input.equals("x"))
{
results.push(results.pop() * results.pop());
}
else if (input.equals("/"))
{
Integer arg2 = results.pop();
results.push(results.pop() / arg2);
}
else if (input.equals("Q") || input.equals("q"))
{
done = true;
}
else
{
// Not an operator—push the input value
results.push(Integer.parseInt(input));
}
System.out.println(results);
}
}
}