/**
*
* @author
*/
public class Expression {

/**
* evaluate an expression
* @param exp the expression
* @return result of the evaluation
* @throws Exception all exception of the method
*/
public static String evaluate(String exp) throws Exception {
   // tokenize the string containing the expression
   Queue<String> tokens = toTokens(exp);
   Stack<Integer> operand = new Stack<>();
   Stack<String> operator = new Stack<>();

   // while there are more tokens
   while (tokens.isEmpty() == false) {
         // get the next token
         String token = tokens.poll();

         // if it is an operand
         if (isOperand(token)) {
            // push it onto the operand stack
            operand.push(Integer.parseInt(token));
         } else if (isLeftParenthesis(token)) {
            // else if it is a left parenthesis
            // push it onto the operator stack
            operator.push(token);
         } else if (isRightParenthesis(token)) {
            // else if it is a right parenthesis
            // while top of the operator stack not a left parenthesis
            while (operator.isEmpty() == false
                     && isLeftParenthesis(operator.peek()) == false) {

               // perform the calculation
               int result = doCalculation(operand, operator);
               // push the result onto the operand stack
               operand.push(result);
            }
            // pop the left parenthesis
            operator.pop();
         } else if (isOperator(token)) {
            // else if it is an operator
            // while the operator stack is not empty and
            // the operator at the top of the stack has higher
            // or the same precedence than the current operator
            while (operator.isEmpty() == false
                     && gePrecedence(token, operator.peek()) == true) {
               // perform the calculation
               int result = doCalculation(operand, operator);
               // push the result onto the operand stack
               operand.push(result);
            }
            // push the current operator on the operators stack
            operator.push(token);
         } else {
            throw new Exception

The purpose of this assignment is to get you to create and use the...