private function hasOperatorInStack()
    {
        $hasOperatorInStack = false;
        if(!$this->operatorStack->isEmpty()) {
            $top = $this->operatorStack->top();
            if(Token::T_OPERATOR == $top->getType()) {
                $hasOperatorInStack = true;
            }
        }

        return $hasOperatorInStack;
    }
private function hasOperatorInStack()
    {
        $hasOperatorInStack = false;
        if(!$this->operatorStack->isEmpty()) {
            $top = $this->operatorStack->top();
            if(Token::T_OPERATOR == $top->getType()) {
                $hasOperatorInStack = true;
            }
        }

        return $hasOperatorInStack;
    }
private function hasOperatorInStack ( ) { $ hasOperatorInStack = false ; if ( ! $ this -> operatorStack -> isEmpty ( ) ) { $ top = $ this -> operatorStack -> top ( ) ; if ( Token :: T_OPERATOR == $ top -> getType ( ) ) { $ hasOperatorInStack = true ; } } return $ hasOperatorInStack ; }
Determine if there is operator token in operato stack

@return boolean
Determine if there is operator token in operato stack