More than 3000 questions in repository. There are more than 900 unanswered questions. Click here and help us by providing the answer. Have a video suggestion. Click Correct / Improve and please let us know.
Ans. Yes, to a certain extent. But the objective for Final class could be beyond just enforcing composition as certain classes might have been created without inheritance or composition in mind.
Help us improve. Please let us know the company, where you were asked this question :
Ans. 1. Enforcing composition over inheritance
2. Restricting overriding of certain methods
3. Final methods are faster than regular instance methods
4. Enforcing Immutability
Help us improve. Please let us know the company, where you were asked this question :
LikeDiscussCorrect / Improve  final class   reasons for final class   restricting inheritance  object oriented programming (oops)  oops concepts expert
Ans. OAuth is an open-standard authorization protocol or framework that describes how unrelated servers and services can safely allow authenticated access to their assets without actually sharing the initial, related, single logon credential. Like using Google or Facebook to login to something.
Help us improve. Please let us know the company, where you were asked this question :
Ans. IP authentication is very restrictive, if IP changes for some reason then getting the new IP white listed on the server firewall could run your day pretty long. I would prefer encrypted password authentication cause it is not affected by IP changes and not limited to a white listed IP, I could use any different machine and get through authentication without any hassle.
Help us improve. Please let us know the company, where you were asked this question :
Ans. Both Arrays and ArrayLists are used to store elements. Elements can be either primitives or objects in case of Arrays, but only objects can be stored in Arraylist. Array is a fixed length data structure while arraylist is variable length collection class. Once created, you cannot change the size of the arrays, but arraylists can dynamically resize itself when needed.Another notable difference between Arrays and Arrayslist is that arary is part of core java programming and array list is part of collection classes
Ans. Just like people , AWS resources too have execution roles or permissions. Seems like in such a situation Lambda function may not have sufficient privileges to perform operations on S3. For example - The execution role of Lambda may just have read permissions on S3 and we may be trying to perform PutObject operation.
Help us improve. Please let us know the company, where you were asked this question :
Ans. Abstract classes can take care of that to a certain extent. Though they are little heavier than Interfaces but An abstract class with all abstract methods and no instance variables will be able to help with everything that currently an interface does.
The only problem is that a class can only extend one class whereas it can implements multiple interfaces and that is the reason Interfaces were introduced in Java, i.e to get over the problem of multiple inheritance.
Help us improve. Please let us know the company, where you were asked this question :
Ans. Service ( EC2, Lambda etc )
AMI ( Operating System and Softwares )
Instance Type ( T,M, R etc )
EBS ( Volume Type , Size )
Price Class ( OnDemand, Dedicated etc )
Help us improve. Please let us know the company, where you were asked this question :
Ans. Base Class is a relative term used to signify the Parent class in Parent - Child or Base - derived relationship.
Derived Class is a relative term used to signify the Child class in Parent - Child or Base - derived relationship.
Abstract Class is a class that is not allowed to be instantiated and hence can serve only a base class for it's usage.
Concrete Class is the class which is supposed to be instantiated and hence provide definition for all implementing interface methods and extending abstract methods.
Help us improve. Please let us know the company, where you were asked this question :
Ans. Automated Backups are deleted automatically whereas Snapshots are preserved. Upon terminating RDS instance , AWS gives a warning about that and requests to create a final snapshot before terminating the instance.
Help us improve. Please let us know the company, where you were asked this question :