- 搜標(biāo)題
- 搜題干
- 搜選項
單項選擇題
有Father類和Daughter類，Daughter的聲明如下： class Daughter extends Father{...}則下面代碼段中發(fā)生了向上轉(zhuǎn)型的是（）。
A.Father f = new Daughter();
B.Daughter d = new Father();
C.Father f= new Father();
D.Daughter d = new Daughter();
