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)
class Foo { public static void main(String [] args) { int x = 0; int y = 4; for(int z=0; z 〈 3; z++, x++) { if(x 〉 1 & ++y 〈 10) y++; } System.out.println(y); } } 結(jié)果是什么?()
A.6 B.7 C.8 D.10