Interview Questions and Answers for 'T' | Search Interview Question - javasearch.buggybread.com

Javasearch.buggybread.com

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.

Submit Question

Interview Questions and Answers - Order By Newest

next 30

Q1121. Difference between multiple and multi level inheritance ?

Ans. Multiple Inheritance refers to the concept of a class inheriting multiple classes. Example - Class C extends Class A ,Class B. This is not allowed in Java.

Multilevel Inheritance refers to the concept of Inheritance in a chain. Example - Class B extends Class A, Class C extends Class B. This is permitted in Java.

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

_{Like Discuss Correct / Improve inheritance object oriented programming (oops) oops concepts multiple inheritance object oriented programming (oops) oops concepts multi level inheritance object oriented programming (oops) oops concepts Basic frequent}

Q1122. What is meant by size and index of a collection ?

Ans. As the name suggest size is the size of collection / data structure i.e number of elements or memory utilized by the collection.

Index is the position of an element in a collection or data structure.

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

_{Like Discuss Correct / Improve collection index of collection size of collection Basic}

Q1123. What is a classpath in Java ?

Ans. Classpath is the parameter for JVM to look for java classes ( .class files ) that are to be looad by class loader

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

_{Like Discuss Correct / Improve classpath Asked in 1 Companies basic}

Q1124. Write a class explaining builder pattern ?

Ans.

public class BuggyBread { 



   private String element1; 



   private String element2; 



   private BuggyBread(String element1, String element2){ 

      this.element1 = element1; 

      this.element2 = element2; 

   } 



   public static class Builder { 

    

      private String element1; 



      private String element2; 



      Builder(BuggyBread buggybread){ 

         element1 = buggybread.element1; 

         element2 = buggybread.element2; 

      } 



      Builder withElement1(String element1){ 

         this.element1 = element1; 

         return this; 

      } 



      Builder withElement2(String element2){ 

         this.element2 = element2; 

         return this; 

      } 



      BuggyBread build(){ 

         BuggyBread buggybread = new BuggyBread(element1,element2); 

         return buggybread; 

      } 

   } 

}

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

_{Like Discuss Correct / Improve builder pattern builder class}

Try 1 Question(s) Test

Q1125. What is the difference between = and == in Java ?

Ans. = is the assignment operator that assigns the result of the expression on the right to the variable on the left, whereas

== is the operator to check object equality to see if the reference on left and right are pointing to the same object. For primitive types, its used to check if both variables holds the same value.

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

_{Like Discuss Correct / Improve = == assignment operator object equality difference between Basic}

Q1126. How is == operator different for objects and primitive types ?

Ans. For objects or references, == operator check if the reference on left and right points to the same object.

For primitive types or variables, == operator check if the variable on left and right holds the same value.

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

_{Like Discuss Correct / Improve == object equality operator Basic}

Q1127. What are the benefits of Enums ?

Ans. Enums in Java are used to declare predefined objects and then reuse them. they offer many benefits

1. Enum instance are type safe and thread safe.

2. Enum instances are singleton and hence reused.

3. If we use Enums with Switch , It makes sure that the passed argument is either of its instance and hence provides a safeguard.

4. If we use Enum with Sorted Collections we can sort the elements with a predefined priorities ( as per constant declaration in enum )

5. We can use Enum as a Factory by defining its constructor.

6. We can store related constant data within enum. For example - If we know the values for the map upfront, we can alternatively use an enum.

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

_{Like Discuss Correct / Improve Asked in 6 Companies}

Q1128. Have you heard of Ban Duplicate Classes Maven enforcer plugin ? What is its use ?

Ans. Yes , we have been using this plugin with our projects and its purpose is to warn and stop the Build if there are duplicates of the same package and class are being carried either directly or through transitive dependencies. the duplicate could be coming through different types of dependencies or through different versions of the same dependency. Its purpose is to make sure that there is only one copy thats being used at compile time and runtime and hence shouldnt later result in runtime problems.

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

_{Like Discuss Correct / Improve maven ban duplicate classes enforcer plugin}

Q1129. How to tackle duplicate classes in maven build ?

Ans. The simplest way is to ignore them if Maven enforcer plugin is complaining about it but it may lead to runtime problems later.

We can do the dependency:tree to see from where these duplicate ones are coming and hence can exclude the duplicate one.

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

_{Like Discuss Correct / Improve maven ban duplicate classes enforcer plugin}

Q1130. Why Collection interface does not extend Cloneable interface ?

Ans. Here is the list of classes that implements Collections Interface - http://www.buggybread.com/2015/02/java-collections-classes-that-implement.html

Having Collection interface to extend Cloneable interface would mean necessarily implement clone method by all implementing classes. As not all collection classes allow duplicate elements, it makes no sense to clone elements for them.

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

_{Like Discuss Correct / Improve cloneable collections collection interface cloning}

Q1131. What happens to the Exception object after the exception handling is done ?

Ans. As with all other objects its garbage collected after its usage unless its rethrown.

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

_{Like Discuss Correct / Improve exceptions exception handling rare}

Q1132. What are the disadvantages of multithreading ?

Ans. 1. Switching Overheads - Even though multi threading aims at improving performance by reducing the wait time and hence improving overall throughput, there is a cost of switching resources between threads and sometime this cost can surpass the benefits if there isnt much wait for IO or external communication.

2. Debugging is hard with multi threaded code.

3. Deadlock - Execution of multi threaded code many a times lead to deadlock due to shared resources.

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

_{Like Discuss Correct / Improve multithreading threads Asked in 4 Companies}

Q1133. Which is the root interface of Collection classes in Java ?

Ans. java.util.Collection

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

_{Like Discuss Correct / Improve collection interface collections}

Q1134. What is the difference between URI, URL and URN ?

Ans. URI stands for Uniform Resource Indicator
URL stands for Uniform Resource Locator
URN stands for Uniform Resource Name

URI = URL + URN

For ex - http://javasearch.buggybread.com/InterviewQuestions/questionSearch.php?keyword=url

This is URI. The string from start till .php is URL whereas keyword=url is URN.

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

_{Like Discuss Correct / Improve url urn uri web address internet address Asked in 1 Companies}

Q1135. In this url

http://javasearch.buggybread.com/InterviewQuestions/questionSearch.php?searchOption=label&keyword=url

What is protocol , domain , path and query param ?

Ans. the web URI starts with the protocol which is http in this case, javasearch.buggybread.com is the domain in this case which is a subdomain of buggybread.com, /InterviewQuestions is the path, questionSearch.php is the resource, searchOption and keyword are query params.

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

_{Like Discuss Correct / Improve url internet address}

Q1136. What is the character limit of url and doesn it apply to GET and POST Requests ?

Ans. Its 2048 and Yes it applies to get request but not POST. As in Get Request , elements are passed as part of the url, this limit applies to Get requests.

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

_{Like Discuss Correct / Improve url internet address}

Q1137. Design a Library system ?

Ans. Following Tables can be created

ASSET - Entity Table With foreign key reference to Table AssetType

ASSET_TYPE - Entity Table specifying information related to Asset Type like Books, CDs etc.

MEMBER - Registration information for the member

MEMBERSHIP_TYPE - Membership Types provided by Library

MEMBERSHIP - Relation table with foreign key for MEMBER ,

MEMBERSHIP_TYPE

ASSET_ISSUE_LEDGER - Relationship between MEMBER and ASSET. This specify the issue of particular asset to a particular member.

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

_{Like Discuss Correct / Improve design Asked in 1 Companies}

Q1138. Write code for Binary tree traversal ?

Ans. http://javabeat.net/binary-search-tree-traversal-java/

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

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

Q1139. Explain what happens when insertion is performed in case of ArrayList and LinkedList.

Ans. Array List works on Array and when we add an element in middle of the list, Array List need to update the index of all subsequent elements. I the capacity is full, it even may need to move the whole list to a new memory location . Linked List works on Double linked list algorithm and all it has to do is to adjust the address of the previous and next elements.

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

_{Like Discuss Correct / Improve arraylist vs linkedlist collections list Asked in 2 Companies}

Q1140. How to Bulk upload the data into Oracle database?

Ans. We can use external table feature of Oracle.

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

_{Like Discuss Correct / Improve Asked in 1 Companies Intermediate}

Q1141. Can there be a Thread without a Process ?

Ans. No.

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

_{Like Discuss Correct / Improve Thread Process Asked in 1 Companies Basic}

Q1142. Can we have an inner class within Interface ?

Ans. Yes, we can define an inner class within interface.Inside the interface, the inner class is implicitly public static.

So the following is legit in Java

public interface BuggyBreadInterface {
   void doSomething();

   public class BuggyBreadClass implements BuggyBreadInterface{
      void doSomething(){
         System.out.println("Do something");
      }
   }
}

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

_{Like Discuss Correct / Improve inner classes inner class in interface nested classes}

Q1143. Is it a valid identifier in Java ?

int 123Abc = 5;

Ans. No, identifier in java cannot start with a numeral.

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

_{Like Discuss Correct / Improve identifiers}

Q1144. What is the difference between Collections.emptyList() and creating new instance of List using new ?

Ans. But Collections.emptyList() returns an Immutable list whereas new arraylist() creates a mutable list.

Advantage of getting an empty list using Collections.emptyList is that it returns a singleton list which can be shared among many references and hence made immutable. This is good fit for situations where we would like to initialize a list to basic minimum empty to avoid null pointer exception.

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

_{Like Discuss Correct / Improve collections Collections.emptyList immutable immutability immutability}

Frequently asked Design Pattern interview question.

Q1145. What is a prototype design pattern ?

Ans. The prototype pattern is a creational design pattern. It is used when the type of objects to create is determined by a prototypical instance, which is cloned to produce new objects. Prototype is used when we need duplicate copies of objects.

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

_{Like Discuss Correct / Improve design pattern prototype design pattern cloning Asked in 11 Companies intermediate}

Q1146. Write a Test Case using Mock ?

Ans. http://javasearch.buggybread.com/CodeSnippets/searchCodeSamples.php?keyword=mock&category=code

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

_{Like Discuss Correct / Improve Junit Mock Asked in 1 Companies}

Very frequently asked.

Q1147. What is the use of synchronized keyword ?

Ans. Synchronize is used to achieve mutual exclusion i.e at one time, the segment of the code, method that has been declared synchronized should be executed by single thread only and hence the lock needs to be retrieved before executing the segment and then released.

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

_{Like Discuss Correct / Improve threads multithreading synchronized Asked in 5 Companies basic frequent}

Q1148. Write an SQL Statement to add a foreign key constraint in oracle ?

Ans. ALTER TABLE <Table_Name> ADD CONSTRAINT <Constraint_Name> FOREIGN KEY (<Column_Name>) REFERENCES <Foreign_Table>(<Foreign_Column>);

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

_{Like Discuss Correct / Improve database add foreign key constraint}

Q1149. How to Change Default Boot Kernel in Linux ?

Ans. https://www.redhat.com/archives/rhl-list/2005-April/msg04167.html

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

_{Like Discuss Correct / Improve unix change default kernel Asked in 1 Companies}

Q1150. What is a Test Dependency Scope in Maven ?

Ans. This scope indicates that the dependency is not required for normal use of the application, and is only available for the test compilation and execution phases. This scope is not transitive.

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

_{Like Discuss Correct / Improve maven Asked in 2 Companies}

previous 30

next 30