public class RPNevaluator {
    private StringBuffer outputBuffer;
    private Stack <Double> myStack = new Stack <Double> ();

    RPNevaluator( String inputString ) {
        outputBuffer = new StringBuffer();
        StringTokenizer sTok = new StringTokenizer ( inputString, "+-/* ", true);
        String temp;

        while (sTok.hasMoreTokens()) {
            temp = ( String ) sTok.nextElement();
            switch ( temp.charAt(0)) {
            case '+':
                double valueA = ( myStack.pop() + " " );
                double valueB = ( myStack.pop() + " " );

                myStack.push(temp);
                break;
            case '-':
                outputBuffer.append( myStack.pop() + " " );
                myStack.push(temp);
                break;
            case '*':
                outputBuffer.append( myStack.pop() + " " );
                myStack.push(temp);
                break;
            case '/':
                outputBuffer.append( myStack.pop() + " " );
                myStack.push(temp);
                break;
            case ' ':
                break;
            default:
                outputBuffer.append( temp +  " " );
                break;
            }
        }
    }
    public static void main(String[] args) {

    }

}


// Operator Button Stuff
// opButtons cannot be done using a loop because their names aren't able to be sequenced. Need to initialize manually
        opButton[0] = new JButton ("+");
        opButton[1] = new JButton ("-");
        opButton[2] = new JButton ("*");
        opButton[3] = new JButton ("/");

[Skip a bunch of lines]

// (WIP) Operator buttons
        // Each operator stores the data before it in a stack
        // Clear display screen to allow addition of new data
        for(int c = 0; c < opButton.length; c++){
            if (evt.getSource()== opButton[c]){
                display.setText(display.getText()+numButton[c].getText());
            } // End of if statement
        } // End of for loop