3 1 What is the output of running the class Test in the following co

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3.1 What is the output of running the class Test in the

following code?

interface A { void print();

}

class C {}

class B extends C implements A { public void print() { }

}

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\");

}

a. Nothing.

b is an instance of A.

b is an instance of C.

b is an instance of A followed by b is an instance of C.

3.2 What is the output of running class C? class A {

public A() {

System.out.println(

\"The default constructor of A is invoked\");

}

class B extends A { public B(String s) {

System.out.println(s);

}

public class C {

public static void main(String[] args) {

B b = new B(\"The constructor of B is invoked\"); }

}

none

\"The constructor of B is invoked\"

\"The default constructor of A is invoked\" \"The

constructor of B is invoked\"

\"The default constructor of A is invoked\"

3.3 Given the following code.

public class Test1 {

public Object max(Object o1, Object o2) { if

((Comparable)o1.compareTo(o2) >= 0) { return o1;

} else { return o2;

}

The program has a syntax error because Test1 does not

have a main method.

The program has a syntax error because o1 is an Object

instance and it does not have the compareTo method.

The program has a syntax error because you cannot cast

an Object instance o1 into

Comparable.

The program would compile if

((Comparable)o1.compareTo(o2) >= 0) is replaced by

(((Comparable)o1).compareTo(o2) >= 0). e. b and d are

both correct.

3.4 Which of the following statements regarding abstract

methods is not true?

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3.1 What is the output of running the class Test in the following code? interface A { } class C {} void print(); class B extends C implements A { public void print() { } } 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\"); } } a. b is b is b is Nothing. an instance of A. an instance of C. an instance of A followed by b is an instance of C. 3.2 What is the output of running class C? class A { public A() { System.out.println( \"The default constructor of A is invoked \"); } } class B extends A { public B(String s) { System.out.println(s); } } public class C { public static void main(String[] args) { B b = new B(\"The constructor of B is invoked \"); } none \"The constructor of B is invoked \" \"The default constructor of A is invoked \" \"The constructor of B is invoked\" \"The default constructor of A is invoked\" 3.3 Given the following code. public class Test1 { public Object max(Object o1, Object o2) { ((Comparable)o1.compareTo(o2) >= 0) { } else { return o2; } } } } if return o1; The program has a syntax error because Test1 does not have a main method. The program has a syntax error because o1 is an Object instance and it does not have the compareTo method. The program has a syntax error because you cannot cast an Object instance o1 into Comparable. The program would compile if ((Comparable)o1.compareTo(o2) ...
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