public String infixToPostfix(){ String postFix = textfield.getText(); //read in infix expression e.g "(12-3) *2 + 3 * 4" //implement using //String delims = "+-*/() "; //StringTokenizer strToken = new StringTokenizer(expression, delims, true); return postFix; //returns postfix expression e.g. "12 3 - 2 * 3 4 * +"

 }