Interview Questions and Answers - Order By Newest Q2341. How would you test a Twitter application ? Testing
This question was recently asked at 'Slalom'.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  solution  testing Asked in 1 Companies Q2342. Write a calculator and find if a character appears more than n times ? Design
This question was recently asked at 'Mercury Systems'.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   Asked in 1 Companies Q2343. Can we keep application configuration at different places and what could be the consideration for choosing multiple places for doing so ? Design
Ans. Yes an application can have configuration stored at multiple places. Factors that could facilitate such a design could be
1. Type of config information - We may have a case to store confidential information differently than other regular config value
2. Environment - We may like to have a base config ( defined in application package ) and then a different override mechanism in different environments.
3. Centralization - Sometime some configs need to be shared across application and hence centralized.
4. Testing - Testing against config may not be possible in some enviornments in certain cases and hence additional config store might be kept for testing purpose only. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  Design  Solution Q2344. Do you think it's a good practice to keep passwords in config files ? Solution
Ans. We can keep them in config as encrypted values. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Q2345. How to write an iterator for an iterator of iterators? Core Java
Ans. CustomArrayList myarrayList = new CustomArrayList();
myarrayList.add("Value 1");
myarrayList.add("Value 2");
myarrayList.add("Value 3");
for (String string : myarrayList) {
System.out.println(string);
}
package sample.utils;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class CustomArrayList implements Iterable {
private ArrayList mylist = new ArrayList();
public void add(T t) {
this.mylist.add(t);
}
@Override
public Iterator iterator() {
return new CustomIterator(mylist);
}
class CustomIterator implements Iterator {
private int indexPosition = 0;
private List internalList;
public CustomIterator(List internalList) {
this.internalList = internalList;
}
@Override
public boolean hasNext() {
if (internalList.size() >= indexPosition 1) {
return true;
}
return false;
}
@Override
public E next() {
E val = internalList.get(indexPosition);
indexPosition ;
return val;
}
}
} Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  iterator Asked in 1 Companies Q2346. What are the disadvantages of binary search trees? Algorithm
This question was recently asked at 'ServiceNow'.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  binary search tree Asked in 1 Companies Q2347. Please explain the architecture of our application through a diagram ? General
This question was recently asked at 'Alfresco Software,Ancestry'.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   Asked in 2 Companies Q2348. How many heaps will be there with 3 threads ? Core Java
Ans. All threads share a common heap.
Each thread has a private stack, which it can quickly add and remove items from. This makes stack based memory fast, but if you use too much stack memory, as occurs in infinite recursion, you will get a stack overflow. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  memory management  heap memory Asked in 1 Companies Q2349. What does 'variable hoisting' mean? JavaScript
Ans. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q2350. Explain when you would decide to use open authentication ? Authentication
Ans. Google OAuth can be used when we want to grant the access of our google credentials to the service provider ( most likely a cloud-based mobile application) by using the option ' Login via Google' Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  open authentication Asked in 1 Companies Q2351. Why Hadoop serialized data types are not using in Spark serialization ? BigData
This question was recently asked at 'Tavant Technology'.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   Asked in 1 Companies Q2352. Explain CloneNotSupportedException ? Core Java
Ans. If we do not mention, Cloneable Interface to the Class which we want to Clone then we get this exception, only if we try to clone an object
Like:
public class TestClone{
@Override
protected Object clone() throws CloneNotSupportedException {
return super.clone();
}
}
In Main, You try to do:
TestClone clone = new TestClone();
TestClone clone2 = (TestClone) clone.clone();
You will get CloneNotSupportedException.
Just add -> public class TestClone implements Cloneable {
and things are fixed. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  exceptions handling  cloning Q2353. Does abstract class have public constructor? Core Java
Ans. Yes, an abstract class can have a constructor in Java. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  abstract class  public constructor Asked in 1 Companies Q2354. What measures would you take to avoid Java threading issues in a multi-threaded environment ?
This question was recently asked at 'Fifth Third Bank'.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   Asked in 1 Companies Ans. Yes Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  aws param store  amazon param store  aws lambda  amazon lambdaAns. No HashMap isn't synchronized. ConcurrentHashMap and Hashtable are synchronized. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  hashmap  synchronization Q2357. Is ConcurrentHashMap synchronized ? Core Java
Ans. Yes, ConcurrentHashMap is synchronized. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  ConcurrentHashMap Q2358. Difference between equals and compareTo in Java ? Core Java
Ans. "equals" is the method of object class which is supposed to be overridden to check object equality. x.equals(y) means the references x and y are holding objects that are equal.
The compareTo() method is used for comparing two objects in Java. It is usually defined for the classes whose objects needs to be ordered through Comparable interface or need to be part of an ordered collection like TreeSet or TreeMap. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  equals  compareTo  equals vs compareTo Q2359. Why is String a class in Java ? Core Java
Ans. 1. Creating a class helps in specifying operations on the Strings like length , sub string , concatenation etc.
2. It acts as a Wrapper class for "Array of Characters" and hence facilitates it's usage in collections, assignment to null.
3. Immutability of String objects facilitates in reuse , security and caching. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  string class Q2360. What is the difference between Encapsulation and encryption ? Networking
Ans. Encapsulation is the process of wrapping the data with another layer to be transported across the network with the source and destination details on just like the analogy of wrapping letter in envelope with the source and destination details on the envelope. Encryption on the other hand is the process of hashing text or transforming the data in a form that is not readable except you have access to the key use to decrypt it. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Q2361. What is the difference between final and static in java ? Core Java
Ans. final keyword is used to restrict the user from modifying the variable, extending the class and overriding a method
static keyword is used for memory management which can be used for variable, class, method where in it belongs to the class not to the instance of object Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 2 Companies Q2362. difference between ArrayList and array ? Core Java
Ans. ArrayList is a variable length collection class whereas arrays are fixed length primitive structure.
We can use generics with arraylist but not with arrays.
We can store primitive data types within arrays but can't with ArrayList. In ArrayList that needs to be converted to Wrapper objects.
Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  arraylist  arrays  collection classes  collections basic   frequent Q2363. Difference between ArrayList and HashSet ? Core Java
Ans. ArrayList is a list , i.e an implementation of List interface whereas HashSet is a Set and an implementation of Set interface. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  arraylist  hashset Q2364. Difference between TreeMap and SortedMap ? Core Java
Ans. sortedMap is an interface ,while TreeMap is an implementation of sortMap.
We can not create an instance of sortedMap but we can create an instance of treeMap Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  treemap  sortedmap Q2365. Difference between HashMap and Dictionary in Java ? Core Java
Ans. HashMap implements the Map interface while the Dictionary does not.
HashMap was introduced after HashTable and Dictionary.
Dictionary is currently obsolete in java. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  hashmap  dictionary class Q2366. Difference between System.getEnv and System.getProperties ? Core Java
Ans. System.getEnv gets the environment variables where System.getProperties gets Java properties. Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  System.getEnv  System.getProperties  environment variables Q2367. Can we load environment variables into Properties in Java ? How ? Core Java
Ans. Yes
new Properties().putAll(System.getenv()); Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  java.util.properties  environment variables Q2368. If you are asked to test an application without any documentation, What type of testing will you do ? Testing
Ans. White Box Testing
Unit Testing
Ad Hoc Testing Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve   Asked in 1 Companies Q2369. Sort an Employee Object based on Name or Age Database
Ans. Use Comparable or Comparator interface Help us improve. Please let us know the company, where you were asked this question : Like Discuss Correct / Improve  sql query Asked in 1 Companies Q2370. What is cluster ?
This question was recently asked at 'idealake information technologies'.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   Asked in 1 Companies