下列程序的输出结果是___________ ?interface A {}class C { }class B extends D imp

1. 以下程序代码的输出为： interface A { } class C { } class B extends D implements A { } public class Test { public static void main(String] args) { B b = new B(); if (b instanceof A) System.out.println("b is an instance of A"); if (b instanceof C) System.out.println("b is an instance of C"); } } class D extends C { } 选项： A: Nothing. B: b is an instance of A C: b is an instance of C D: b is an instance of A followed by b is an instance of C

2.以下代码行中运行Test类的输出是？interface A {} class C { } class B extends D implements A {} public class Test { public static void main(String[] args) { B b = new B(); if (b instanceof A) System.out.println("b is an instance of A"); if (b instanceof C) System.out.println("b is an instance of C"); }} class D extends C { }选项： A:什么都不输出; B:输出：b is an instance of A; C:输出：b is an instance of C; D:输出：b is an instance of Ab is an instance of C

3. 单选题Show the output of running the class Test in the following code lines: ( )Interface A {}Class C {}Class B extends D implements A {}Public class Test {Public static void main(String] args) {B b = new B();If (b instanceof A)System.out.println("b is an instance of A");If (b instanceof C)System.out.println("b is an instance of C");}}Class D extends C {} 选项： A:Nothing. B:b is an instance of A C:b is an instance of C D:b is an instance of A followed by b is an instance of C

if (b instanceof C)
System.out.println("b is an instance of C");
}
}

class D extends C {
}

选项： A:

没有输出

B:

b is an instance of A

C:

b is an instance of C.

D:

输出b is an instance of A，然后是b is an instance of C.

">4.如下程序的运行结果为：（）。

interface A {
}

class C {
}

class B extends D implements A {
}

public class Test {
public static void main(String] args) {
B b = new B();
if (b instanceof A)
System.out.println("b is an instance of A");
if (b instanceof C)
System.out.println("b is an instance of C");
}
}

class D extends C {
}