Which instantiates an instance of Inner?

Which instantiates an instance of Inner?

A. new Inner(); // At line 3

B. new Inner(); // At line 8

C. new o.Inner(); // At line 8

D. new Outer.Inner(); // At line 8//new Outer().new Inner()

答案如下：

publicclass Outer {

    publicvoid someOuterMethod() {

       // Line 3

       new Inner();//放在这里不出错

    }

    publicclass Inner {

    }

 

    publicstaticvoid main(String[] argv) {

       Outer o= new Outer();

       // Line 8

       //o不能够被解释成为一种类型，出错

       //new o.Inner();

       /**

        *下面两种用法，都报下面的错误：

        *NoenclosinginstanceoftypeOuterisaccessible.

        *Mustqualifytheallocationwithanenclosinginstance

        *oftypeOuter(e.g.x.newA()wherexisaninstanceofOuter)

        */   

       //new Outer.Inner();

       //new Inner();      

    }

}