Set 26

Multiple Choice Question

QID: 
207

Which is the first line that will cause compilation to fail in the following program?

// Filename: A.java

class A{
public static void main(String args[]){
A a = new A();
B b = new B();
a = b;  // 1
b = a;  // 2
a = (B) b; // 3
b = (B) a; // 4   } }
class B extends A { }

Select 1 option

A. At Line 1. 
B. At Line 2. 
C. At Line 3. 
D. At Line 4. 
E. None of the above. 

Multiple Choice Question

QID: 
206

Consider :
class A { public void perform_work(){} }
class B extends A { public void perform_work(){} }
class C extends B { public void perform_work(){} }

How can you let perform_work() method of A to be called from an instance method in C?

Select 1 option

A. ( (A) this ).perform_work( );
B. super.perform_work( );
C. super.super.perform_work( );
D. this.super.perform_work( );
E. It is not possible.

Multiple Choice Question

QID: 
205

Consider the following classes:

class A {
public int getCode(){ return 2;}
}
class AA extends A {
public void doStuff() {
}
}

Given the following two declarations, which of the options will compile?

A a = null;
AA aa = null;

Select 4 options

A. a = (AA)aa;
B. a = new AA();
C. aa = new A();
D. aa = (AA) a;
E. aa = a;
F. ((AA)a).doStuff();

Multiple Choice Question

QID: 
204

Consider the following classes:

class A implements Runnable{ ...}
class B extends A implements Observer { ...}
(Assume that Observer has no relation to Runnable.)

and the declarations :

A a = new A() ;
B b = new B();

Which of the following Java code fragments will compile and execute without throwing exceptions?

Select 2 options

A. Object o = a; Runnable r = o;
B. Object o = a; Runnable r = (Runnable) o;
C. Object o = a; Observer ob = (Observer) o ;
D. Object o = b; Observer o2 = o;
E. Object o = b; Runnable r = (Runnable) b;

Multiple Choice Question

QID: 
203

Consider the following program:

class Game {
public void play() throws Exception {
System.out.println("Playing...");
}
}
class Soccer extends Game {
public void play(String ball) {
System.out.println("Playing Soccer with "+ball);
}
}
public class TestClass {
public static void main(String[] args) throws Exception {
Game g = new Soccer();
// 1
Soccer s = (Soccer) g;
// 2
}
}

Which of the given options can be inserted at //1 and //2?

Select 2 options

A. It will not compile as it is.
B. It will throw an Exception at runtime if it is run as it is.
C. g.play(); at //1 and s.play("cosco"); at //2
D. g.play(); at //1 and s.play(); at //2
E. g.play("cosco"); at //1 and s.play("cosco"); at //2

Pages

Search the Web

Custom Search

Searches whole web. Use the search in the right sidebar to search only within javajee.com!!!

Quick Notes Finder Tags

Activities (1) advanced java (1) agile (3) App Servers (6) archived notes (2) ArrayLists (1) Arrays (2) Best Practices (12) Best Practices (Design) (3) Best Practices (Java) (7) Best Practices (Java EE) (1) BigData (3) Chars & Encodings (6) coding problems (2) Collections (15) contests (3) Core Java (All) (52) course plan (2) Database (12) Design patterns (8) dev tools (3) downloads (2) eclipse (9) Essentials (1) examples (14) Exception (1) Exceptions (4) Exercise (1) exercises (6) Getting Started (18) Groovy (2) hadoop (4) hibernate (77) hibernate interview questions (6) History (1) Hot book (4) http monitoring (2) Inheritance (4) intellij (1) java 8 notes (4) Java 9 (1) Java Concepts (7) Java Core (7) java ee exercises (1) java ee interview questions (2) Java Elements (16) Java Environment (1) Java Features (4) java interview points (4) java interview questions (4) javajee initiatives (1) javajee thoughts (3) Java Performance (6) Java Programmer 1 (11) Java Programmer 2 (8) Javascript Frameworks (1) Java SE Professional (1) JSP (1) Legacy Java (1) linked list (3) maven (1) Multithreading (16) NFR (1) No SQL (1) Object Oriented (9) OCPJP (4) OCPWCD (1) OOAD (3) Operators (4) Overloading (2) Overriding (2) Overviews (1) policies (1) programming (1) Quartz Scheduler (1) Quizzes (17) RabbitMQ (1) references (2) resources (1) restful web service (3) Searching (1) security (10) Servlets (8) Servlets and JSP (31) Site Usage Guidelines (1) Sorting (1) source code management (1) spring (4) spring boot (3) Spring Examples (1) Spring Features (1) spring jpa (1) Stack (1) Streams & IO (3) Strings (11) SW Developer Tools (2) testing (1) troubleshooting (1) user interface (1) vxml (8) web services (1) Web Technologies (1) Web Technology Books (1) youtube (1)