9.5 装箱与拆箱

demo1 integer ,int 为例

        Integer obj = new Integer(10);// 装箱
        int num = obj.intValue();// 拆箱
        System.out.println(num * num);

demo2 double,Double为例

        Double obj = new Double(10.1);//装箱
        double num = obj.doubleValue();//拆箱
        System.out.println(num * num);

demo3 boolean,Boolean为例

       Boolean obj = new Boolean(true);//装箱
        boolean num = obj.booleanValue();//拆箱
        System.out.println(num);