private Object calculate(LinkedList<Object> el2){
        if(el2.peek() instanceof Operator){
            Operator obj = (Operator) el2.peek();
            return obj.calculate();
        }
        if(el2.peek() instanceof Elobj){
            return ((Elobj) el2.peek()).fetchVal();
        }
        return el2.peek();
    }
private Object calculate(LinkedList<Object> el2){
        if(el2.peek() instanceof Operator){
            Operator obj = (Operator) el2.peek();
            return obj.calculate();
        }
        if(el2.peek() instanceof Elobj){
            return ((Elobj) el2.peek()).fetchVal();
        }
        return el2.peek();
    }
private Object calculate ( LinkedList < Object > el2 ) { if ( el2 . peek ( ) instanceof Operator ) { Operator obj = ( Operator ) el2 . peek ( ) ; return obj . calculate ( ) ; } if ( el2 . peek ( ) instanceof Elobj ) { return ( ( Elobj ) el2 . peek ( ) ) . fetchVal ( ) ; } return el2 . peek ( ) ; }
计算
计算