class Car implements Serializable { } class Ford extends Car { } 如果試圖序列化一個(gè)Ford實(shí)例,結(jié)果為()
A.編譯失敗 B.一個(gè)對(duì)象被序列化 C.兩個(gè)對(duì)象被序列化 D.運(yùn)行時(shí)異常被拋出
下述代碼執(zhí)行后,可以被垃圾收集器收集的對(duì)象是哪一個(gè)() Student stua; stua = new Student(“Mike”); Student stub; stub = stua; stua = new Student(“Jack”);
A.Student(“Mike”) B.stua C.stub D.以上都不是
public class Pet{} public class Cat extends Pet{} 執(zhí)行代碼 Cat c = new Cat(); Pet p = (Pet)c; 下列哪項(xiàng)是正確的?
A.Pet p = (Pet)c正常執(zhí)行 B.Pet p = (Pet)c編譯錯(cuò)誤 C.Pet p = (Pet)c運(yùn)行錯(cuò)誤 D.以上都不對(duì)