Question 1 of 25
Hints left: 3
Q1
In Java, can a class implement an interface and extend an abstract class simultaneously?
Q2
In Java, can an abstract class have private methods with implementations?
Q3
Suppose A is an abstract class, B is a concrete subclass of A, and both A and B have a default constructor. Which of the following is correct? 1. A a = new A(); 2. A a = new B(); 3. B b = new A(); 4. B b = new B();
Q4
What is the result of the following code snippet? abstract class MyAbstract { static void myMethod() { System.out.println("Static Method"); } } class MyClass extends MyAbstract { public static void main(String[] args) { MyAbstract.myMethod(); } }
Q5
What will be the output? interface A{ public void method(); } class One{ public void method(){ System.out.println("Class One method"); } } class Two extends One implements A{ public void method(){ System.out.println("Class Two method"); } } public class Test extends Two{ public static void main(String[] args){ A a = new Two(); a.method(); } }
Q6
What is the result of the following code snippet? abstract class MyAbstract { MyAbstract() { System.out.println("Constructor"); } } class MyClass extends MyAbstract { public static void main(String[] args) { MyClass obj = new MyClass(); } }
Q7
Which two of the following are legal declarations for abstract classes and interfaces? 1. final abstract class Test {} 2. public static interface Test {} 3. final public class Test {} 4. protected abstract class Test {} 5. protected interface Test {} 6. abstract public class Test {}
Q8
What is the purpose of the "final" keyword in Java?
Q9
In Java, can an abstract class have static methods with implementations?
Q10
In Java, can an abstract class have constructors?
Q11
In Java, declaring a class abstract is useful
Q12
Which of the following class definitions defines a legal abstract class?
Q13
What is the result of the following code snippet? abstract class MyAbstract { private void myMethod() { System.out.println("Private Method"); } } class MyClass extends MyAbstract { public static void main(String[] args) { MyClass obj = new MyClass(); obj.myMethod(); } }
Q14
Given the following piece of code: public class School{ public abstract double numberOfStudent(); } which of the following statements is true?
Q15
Given the following piece of code: public interface Guard{ void doYourJob(); } abstract public class Dog implements Guard{ } which of the following statements is correct?
Q16
Which of the following is a correct interface?
Q17
Which of the following statements regarding abstract classes are true?
Q18
What is the result of the following code snippet? interface MyInterface { static void myMethod() { System.out.println("Static Method"); } } class MyClass implements MyInterface { public static void main(String[] args) { MyInterface.myMethod(); } }
Q19
interface Base{ boolean m1 (); byte m2(short s); } which two code fragments will compile? 1. interface Base2 implements Base {} 2. abstract class Class2 extends Base { public boolean m1(){ return true; }} 3. abstract class Class2 implements Base {} 4. abstract class Class2 implements Base { public boolean m1(){ return (7 > 4); }} 5. abstract class Class2 implements Base { protected boolean m1(){ return (5 > 7) }}
Q20
In Java, can an abstract class have default methods with implementations?
Q21
Which of the following declares an abstract method in an abstract Java class?
Q22
In Java, can an interface have static methods with implementations?
Q23
interface Test{ int p = 10; //line 1 public int q = 20; //line 2 public static int r = 30; //line 3 public static final int s = 40; //line 4 } Which of the above line will give compilation error?
Q24
Determine output of the following code. interface A { } class C { } class D extends C { } class B extends D implements A { } public class Test extends Thread{ 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"); } }
Q25
What will happen after compiling this program code? abstract class MyClass{ //line 1 private int a, b; public void call(int a, int b){ this.a = a; this.b = b; System.out.print(a+b); } } public class Test{ public static void main(String args[]){ MyClass m = new MyClass(); //line 2 m.call(12,25); } }