Search Interview Questions | 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. |
|
| ||||
Interview Questions and Answers - Order By Rating | ||||
| ||||
This question was recently asked at 'Bristlecone,Amazon Lab126,Amazon,Microsoft,Facebook,NCR,Google'.This question is still unanswered. Can you please provide an answer. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  arrays  code  coding Asked in 7 Companies   frequent | ||||
| ||||
Ans. Use hashCode() which returns an integer value, generated by a hashing algorithm | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  hash codes  hashcode Asked in 1 Companies | ||||
| ||||
This question is still unanswered. Can you please provide an answer. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve   | ||||
| ||||
This question is still unanswered. Can you please provide an answer. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  mmutable  immutability  immutabilit | ||||
| ||||
This question was recently asked at 'Overstock.com'.This question is still unanswered. Can you please provide an answer. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  mmutable  immutability  immutabilit Asked in 1 Companies | ||||
| ||||
This question is still unanswered. Can you please provide an answer. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve   | ||||
| ||||
This question is still unanswered. Can you please provide an answer. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve   | ||||
| ||||
Ans. To fetch records from a database, you would use SELECT statements | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve   Asked in 1 Companies | ||||
| ||||
Ans. Yes , but only the read performance in case we don't need to modify it much. In case we need to modify it a lot , it creates write performance overheads as we would need to create many news objects instead of just changing one. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  immutable  immutability objects  immutability | ||||
| ||||
Ans. Immutable objects relieves us from the problems of inconsistencies and security and helps with better read performance but at the same time are write performance and storage overheads. In case any modification is required , a new object is created and thus creating multiple copies of it. This is the reason we use StringBuffer / StringBuilder when we have to append some text multiple times and then create a String out of it. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  immutable  immutability objects  immutability | ||||
| ||||
Ans. Oracle having following types of joins these are also called 8i joins. There are: 1. Equi (or) Inner join 2. Non Equi join 3.Self join 4.Outer join Oracle also support the 9i (or) ANSI standard joins.There are: 1.Inner join 2.Left outer join 3.Right outer join 4.Full outer join 5.Natural join | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  sql joins  sql Asked in 2 Companies | ||||
| ||||
This question was recently asked at 'LumenData'.This question is still unanswered. Can you please provide an answer. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  database  rdbms  dbms  dbms vs rdbms Asked in 1 Companies basic | ||||
| ||||
Ans. LinkedList maintains the insertion order in collection. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  collections Asked in 1 Companies | ||||
| ||||
Ans. It returns all the rows form the left table and matches the rows in both tables. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  database   database joins   left outer join  sql Asked in 2 Companies | ||||
| ||||
Ans. The clustered index determines how the data is stored in the rows of a table.The non-clustered index stores the data at a single place and the indexes are stored at another place. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  clustered vs non clustered index  index  database index Asked in 1 Companies | ||||
| ||||
Ans. The Java collections framework (JCF) is a set of classes and interfaces that implement commonly reusable collection data structures. Although referred to as a framework, it works in a manner of a library. The JCF provides both interfaces that define various collections and classes that implement them. | ||||
Sample Code for Map Sample Code for HashMap Sample Code for Treemap Sample Code for set Sample Code for hashset Sample Code for treeset Sample Code for list Sample Code for arraylist Sample Code for linkedlist Sample Code for queue Sample Code for priorityqueue Sample Code for concurrenthashmap Sample Code for vector Sample Code for stack | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  collections Asked in 9 Companies basic   frequent | ||||
| ||||
Ans. You need to capture heap dump when it's in the healthy state. Start your application. Let it take real traffic for 10 minutes. At this point, capture heap dump. Heap Dump is basically the snapshot of your memory. It contains all objects that are residing in the memory, values stored in those objects, inbound | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  memory leaks  heap dump Asked in 1 Companies intermediate | ||||
| ||||
Ans. There are four main OOP concepts in Java. These are: Abstraction. Abstraction means using simple things to represent complexity. We all know how to turn the TV on, but we don?t need to know how it works in order to enjoy it. In Java, abstraction means simple things like objects, classes, and variables represent more complex underlying code and data. This is important because it lets avoid repeating the same work multiple times. Encapsulation. This is the practice of keeping fields within a class private, then providing access to them via public methods. It?s a protective barrier that keeps the data and code safe within the class itself. This way, we can re-use objects like code components or variables without allowing open access to the data system-wide. Inheritance. This is a special feature of Object Oriented Programming in Java. It lets programmers create new classes that share some of the attributes of existing classes. This lets us build on previous work without reinventing the wheel. Polymorphism. This Java OOP concept lets programmers use the same word to mean different things in different contexts. One form of polymorphism in Java is method overloading. That?s when different meanings are implied by the code itself. The other form is method overriding. That?s when the different meanings are implied by the values of the supplied variables. See more on this below. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  oops  oops concepts Asked in 16 Companies basic   frequent | ||||
| ||||
This question was recently asked at 'Intel'.This question is still unanswered. Can you please provide an answer. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  abstraction  oops concepts Asked in 1 Companies basic | ||||
| ||||
This question is still unanswered. Can you please provide an answer. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  database  rdbms  read optimization | ||||
| ||||
Ans. Usually Relational Databases are optimized for writing. Some exception being usage of indices where indices needs to be updated after insertion and eventually helps with Log(n) reading time. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  read optimization  rdbms  relational database | ||||
| ||||
This question is still unanswered. Can you please provide an answer. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  read optimization   write optimization | ||||
| ||||
Ans. Abstraction is a process of hiding the implementation details and describing only the functionality to the user. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  bstraction  oops concepts  oops principle Asked in 22 Companies | ||||
| ||||
Ans. Cloneable and Serializable are Marker Interfaces, So these are empty interfaces with no variables. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  cloneable  serializable  static variables Asked in 1 Companies | ||||
| ||||
Ans. ConcurrentHashMap uses multiple buckets to store Data and hence avoid read locks which facilitates better performance. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  ashTabl expert   rare | ||||
| ||||
Ans. Immutable objects are thread-safe so you will not have any synchronization issues.Immutable objects are good for Map keys and Set elements, since these typically do not change once created.Immutability makes it easier to write, use and reason about the code (class invariant is established once and then unchanged)Immutability makes it easier to parallelize your program as there are no conflicts among objects.The internal state of your program will be consistent even if you have exceptions.References to immutable objects can be cached as they are not going to change. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  immutable  immutability classes   benefits of immutable  immutability classes Asked in 1 Companies | ||||
| ||||
Ans. string and wrapper class objects | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  immutability  immutable  immutability classes   immutable  immutability collections Asked in 3 Companies | ||||
| ||||
Ans. There is no concept of de referencing with primitive types and hence they are implicitly immutable. Having wrapper classes as mutable offers disadvantages compared to primitive types. Wrapper classes being immutable offer similar advantage as primitive types.It actually overshadows the disadvantage wrapper class could have if they are immutable. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  immutable  immutability classes  wrapper classes | ||||
| ||||
Ans. SELECT MIN(FIELD) FROM (SELECT TOP 2 FIELD FROM TABLE ORDER BY FIELD DESC) or SELECT MAX(FIELD) FROM TABLE WHERE FIELD NOT IN (SELECT MAX(FIELD) FROM TABLE) | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  sql | ||||
| ||||
Ans. We can have 2 entities i.e EMPLOYEE and ADDRESS and can have a relationship Table , EMPLOYEE_ADDRESS having one to may relationship between the two. | ||||
Help us improve. Please let us know the company, where you were asked this question : | ||||
Like Discuss Correct / Improve  database schema   design Asked in 2 Companies | ||||