//converts infix expression to postfix expression
void ArithmeticExpression::convertToPostfix(char *const inFix, char *const postFix)
{

 //create a stack2 object named cow
 Stack2<char> cow;
 cout<<postFix;

 char thing = '(';

 //push a left parenthesis onto the stack
 cow.push(thing);


//append a right parenthesis to the end of inFix array
strcat(inFix, ")");

int i = 0;//declare an int that will control posFix position


//if the stack is not empty
if (!cow.isEmpty())
{

    //loop to run until the last character in inFix array
    for (int x = 0; inFix[x]!= ''; x++ )
    {

        //if the inFix element is a digit
        if (isdigit(inFix[x]))
        {
            postFix[i]=inFix[x];//it is assigned to the next element in postFix array
            i++;//move on to next element in postFix

        }

        //if the inFix element is a left parenthesis
        else if (inFix[x]=='(')
        {
            cow.push(inFix[x]);//push it unto the stack
        }

        //if the inFix element is an operator
        else if (isOperator(inFix[x]))
        {

            char oper2 = inFix[x];//char variable holds inFix operator

            if (isOperator(cow.stackTop()))//if the top node in the stack is an     operator
            {
            while (isOperator(cow.stackTop()))//and while the top node in the stack is an operator
            {

                char oper1 = cow.stackTop();//char variable holds node operator
                if(precedence( oper1, oper2))//if the node operator has higher presedence than node operator
                {
                    postFix[i] = cow.pop();//we pop such operator and insert it in postFix array's next element
                    cow.push(inFix[x]);//and push inFix operator unto the stack
                    i++;//move to the next element in posFix
                }

            }
        }
            //if the top node is not an operator
            //we push the current inFix operator unto the top of the stack
            else
            cow.push(inFix[x]);

        }

        //if the inFix element is a right parenthesis
        else if (inFix[x]==')')
        {
            //we pop everything in the stack and insert it in postFix
            //until we arrive at a left paranthesis
            while (cow.stackTop()!='(')
            {
                postFix[i] = cow.pop();
                i++;
            }
            //we then pop and discard left parenthesis
            cow.pop();
        }


    }

     postFix[i]='';

    //print !!postFix array!! (not stack)
    print();//code for this is just cout<<postFix;

}