Interview Questions and Answers for 'T' | Search Interview Question

Interview Questions and Answers - Order By Newest

Q761. If a method definition has been specified in the Base Class and the interface which the class is implementing, Which definition will be picked if we try to access it using Interface Reference and Class object ?

Ans. Base Class Definition will have precedence over the Interface Default method definition.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java java8 default methods}

Q762. Can we access Interface static method using Interface references ?

Ans. No, only using Interface Name.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java java8 static interface methods}

Q763. Can we have default method with same name and signature in the derived Interface as the static method in base Interface and vice versa ?

Ans. Yes , we can do that as static methods are not accessible using references and hence cannot lead to conflict. We cannot do inverse as Default methods cannot be overridden with the static methods in derived interface.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java java8 default methods static interface methods}

Q764. What is the difference between namenode and datanode in Hadoop?

BigData

Ans. NameNode stores MetaData (No of Blocks, On Which Rack which DataNode is stored etc) whereas the DataNode stores the actual Data.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve hadoop at&t Asked in 2 Companies}

Q765. Write a program to see if the number is perfect number or not ?

Core Java

Ans. http://www.c4learn.com/c-programs/program-to-check-whether-number-is.html

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java at&t coding}

Q766. Difference between TCP and UDP ?

Networking

Ans. http://www.cyberciti.biz/faq/key-differences-between-tcp-and-udp-protocols/

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java network programming architecture Cloud Computing Google Cloud Computing (GCP) Amazon Web Services (AWS) Asked in 3 Companies}

Very frequently asked. Usually followed by questions related to private constructor and synchronized access. Frequently asked in JPMorgan and TCS (Based on 2 feedback)

Q767. Explain Singleton Design Pattern ?

Design

Ans. http://www.buggybread.com/2014/03/java-design-pattern-singleton-interview.html

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java design pattern singleton at&t ebay fidelity india united healthcare india Asked in 46 Companies intermediate frequent}

Q768. What should I do if I want to make sure that a particular method of a class is getting called ?

Ans. If its a static method of the class , we can use verify to make sure its getting called.

If its an instance method , We can mock the object and then use verify with the mocked object to make sure that the method is getting called.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve junit mockito mock}

Q769. What is the use of Mockito.any ?

Ans. In case we need to verify that a method is being called with any argument and not a specific argument we can use Mockito.any(Class), Mockito.anyString, Mockito.anyLong etc.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve junit mockito mock mockito.any}

Q770. Name few Java Mocking frameworks ?

Ans. Mockito, PowerMock, EasyMock, JMock, JMockit

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve junit mocking frameworks mock architecture white box testing}

Q771. Write an SQL to find all records having all upper case alphanumeric characters in a field ?

Ans. Select * from Table where field = upper(field)

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve sql database}

Q772. Write an SQL to find all records having all numeric characters in a field ?

Ans. Select * from Table where isnumeric(field) = 1;

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve sql database}

Q773. How can we protect an application from throwing a NullPointerException ?

Ans. By having Null Checks.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve exceptions npe nullpointerexception null checks basic frequent}

Q774. What are the conventions regarding constant variables or static final variables ?

Core Java

Ans. They should be named all in upper case with underscore separating words.

Moreover the name should be such that it identifies the value. For example, if we are using constant for employee Id 123, it should be named something like EMPLOYEE_ID_123 and not EMPLOYEE_ID

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve constants variable names java conventions}

Q775. How do you define a class of constants in Java?

Ans. Make the class as final.
Disable the object construction by making constructor private.
Keep only Static Final Variables declared and Defined at the same time.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java constants constant class java}

Q776. What will the following code do ?

String dateStr = "2011 11 19";
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
Date date = dateFormat.parse(dateStr);
System.out.println(date);

Ans. It will throw the ParseException as the date format doesn't abide with the format of the specified date.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve date utility classes dateformat exception parseexception}

Q777. What will be the output of this code ?

Set mySet = new TreeSet();
mySet.add("4567");
mySet.add("5678");
mySet.add("6789");
for(String s: mySet){
System.out.println(s);
}

Ans. 4567
5678
6789

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java collections set treeset coding code}

Q778. public enum Day {
SUNDAY, MONDAY, TUESDAY, WEDNESDAY,
THURSDAY, FRIDAY, SATURDAY
}

public class Test {
Set mySet = new HashSet();
mySet.add(Day.MONDAY);
mySet.add(Day.SUNDAY);
mySet.add(Day.SATURDAY);

for(Day d: mySet){
System.out.println(d);
}
}

Ans. SUNDAY
MONDAY
SATURDAY

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve enum set collections hashset coding code}

Try 3 Question(s) Test

Q779. What will be the output of the following code ?

enum Day {
   MONDAY,TUESDAY,WEDNESDAY,THURSDAY,FRIDAY,SATURDAY,SUNDAY
}

public class BuggyBread1{
   public static void main (String args[]) {
      Set mySet = new HashSet();
      mySet.add(Day.SATURDAY);
      mySet.add(Day.WEDNESDAY);
      mySet.add(Day.FRIDAY);
      mySet.add(Day.WEDNESDAY);
      for(Day d: mySet){
         System.out.println(d);
      }
   }
}

Ans. FRIDAY , SATURDAY and WEDNESDAY will be printed but the order cannot be determined.

Only one FRIDAY will be printed as Set doesn't allow duplicates. Order cannot be determined as HashSet doesn't maintain elements in a particular order.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java code coding enum set hashset}

Try 3 Question(s) Test

Q780. public class BuggyBread1{

public static void main (String args[]) {
Set<String> mySet = new TreeSet<String>();
mySet.add(""1"");
mySet.add(""2"");
mySet.add(""111"");
for(String d: mySet){
System.out.println(d);
}
}
}

Core Java

Ans. 1
111
2

TreeSet maintains the elements in the ascending order which is identified by the compareTo method. compareTo method in String has been defined such that it results in the natural alphabetic Order. Here the elements in the TreeSet are of String and not of Integer. In String Natural Order, 111 comes before 2 as ascii of 1st character first determines the order.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java code coding set treeset string integer}

Q781. public class BuggyBread1{

public static void main (String args[]) {
Set<Integer> mySet = new TreeSet<Integer>();
mySet.add(1);
mySet.add(2);
mySet.add(111);
for(Integer d: mySet){
System.out.println(d);
}
}
}

Core Java

Ans. 1
2
111

TreeSet maintains the elements in the ascending order which is identified by the compareTo method. compareTo method in Integer has been defined such that it results in the natural numerical Order.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java code coding set treeset}

Q782. Can we extend an Enum ?

Core Java

Ans. No. Enums are final by design.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java enums inheritance object oriented programming (oops) oops concepts yes-no Asked in 1 Companies intermediate}

Q783. What would you do if you have to add a jar to the project using Maven ?

Maven

Ans. If its already there in Maven local repository, We can add that as a dependency in the project pom file with its Group Id, Artifact Id and version.

We can provide additional attribute SystemPath if its unable to locate the jar in the local repository.

If its not there in the local repository, we can install it first in the local repository and then can add it as dependency.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve maven maven dependencies jar architecture}

Q784. Have you ever had problem getting your projects in eclipse refreshed after you made changes in the Pom files ?

Maven

Ans. Yes, It happens many times but I would usually perform mvn eclipse:eclipse and this would resolve the project refresh problems.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve maven maven repository eclipse Asked in 1 Companies}

Q785. What is the difference between compile and install ?

Maven

Ans. Compile compiles the source code of the project

whereas

Install installs the package into the local repository, for use as a dependency in other projects locally

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve maven install build management}

Q786. How to perform a clean install without executing Tests ?

Maven

Ans. mvn clean install -Dmaven.test.skip=true

or

mvn install -DskipTests

or

org.apache.maven.plugins
maven-surefire-plugin

true

within parent POM file.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve maven maven install unit testing unit tests}

Q787. Shouldn't we make a class with all static members is its just expected to be executed as a standalone program with just one thread. Moreover Lets assume that there is no runtime Polymorphism required and there is no need for serialization ?

Design

Ans. Still No in case we are making use of inheritance. we may have problem wherein we have program flow moving across common inherited method and specific methods of the derived class. call made to another static method in the parent class will only access the static class of the Parent class irrespective of the call from any of the derived class.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve static class static vs singleton inheritance}

Q788. Tell me something about AssertionError ?

Core Java

Ans. AssertionError is actually a fatal fault or a bug in the program. We may not like to continue program , request or thread execution if this error occurs as this condition is the assumption to continue further execution.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java error exceptions exception handling assertion error assertionerror}

Q789. Should we create system software ( e.g Operating system ) in Java ?

Core Java

Ans. No, Java runs on a virtual machine called JVM and hence doesn't embed well with the underlying hardware. Though we can create a platform independent system software but that would be really slow and that's what we would never need.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java system software java jvm yes-no yes no java operating system architecture}

Q790. What is Java primarily used for ?

Core Java

Ans. For creating platform independent software applications.

Help us improve. Please let us know the company, where you were asked this question :

_{Like Discuss Correct / Improve java java use architecture}

Search Interview Questions

Help us and Others Improve. Please let us know the questions asked in any of your previous interview.