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

Interview Questions and Answers - Order By Newest

Q791. Do you know of any DB statement that can be used if we would like to insert multiple rows into a table ?

Database

Ans. We can use INSERT ALL.

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

_{Like Discuss Correct / Improve database insert dml statement sql}

Q792. Shall we keep the enumeration name in all capital letters as it contains all constants ?

Ans. Enum is actually a class with pre defined constants. So enum name should follow the convention of the Class name. Though the constant names or the Enum variables should follow the convention of having all capital letters.

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

_{Like Discuss Correct / Improve java enum enumerations java conventions java naming conventions}

Q793. In majority of the situations it won't make much sense whether you append this with the instance method call.Can you tell a situation wherein this keyword would make sense in a instance method ?

Core Java

Ans. Within instance method of the parent class that has other multiple methods that have been overridden by the derived classes.

In such case a simple method call from the common method will always be made to the method definition in the parent class. But If we use this.methodCall , this will be polymorphic and will be made to the respective derived object overriding method.

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

_{Like Discuss Correct / Improve java this keyword java keywords}

Q794. Why is null == null returns true ?

Core Java

Ans. Any reference in java that doesn't point to any object , gets assigned null i.e is a reference to null. Two object references in java are treated equal if they point to the same memory. That's Why null == null results true.

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

_{Like Discuss Correct / Improve java null equality references}

Q795. How is HashSet maintained in memory by Java ?

Core Java

Ans. HashSet is maintained as HashMap by Java with values of the HashSet as Keys of the HashMap and value of the HashMap as the constant PRESENT.

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

_{Like Discuss Correct / Improve ebay java collections hashset hashmap expert}

Q796. What is Closeable ?

Core Java

Ans. A Closeable is an interface which is a source or destination of data that can be closed.

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

_{Like Discuss Correct / Improve closeable interfaces intermediate rare}

Q797. What is the difference between JPA and Hibernate ?

Hibernate

Ans. JPA or Java Persistence API is a standard specification for ORM implementations whereas Hibernate is the actual ORM implementation or framework.

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

_{Like Discuss Correct / Improve jpa hibernate orm architecture technologies Asked in 2 Companies}

Q798. What is the advantage of JPA ?

Database

Ans. Its a specification that guides the implementation of ORM frameworks. Implementations abiding by the specification would mean that one can be replaced with other in an application without much hassle. Only the Features that are added over the specification needs to be taken care of if any such change is made.

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

_{Like Discuss Correct / Improve jpa hibernate orm technologies}

Not frequently asked as it was introduced with Java 8.

Q799. What is the @FunctionalInterface annotation ?

Core Java

Ans. This is an informative annotation that specify that the interface is a functional interface. A Function Interface has only one abstract method and many default methods. Compiler generates an error if the interface specified with the annotation doesn't abide by the specifications for functional interface.

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

_{Like Discuss Correct / Improve java java8 java 8 functional interface default methods}

Q800. Name some Java REST services frameworks ?

Rest

Ans. Jersey , Restlet , RestX, Spring , RestEasy ,Restfulie, Play Framework

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

_{Like Discuss Correct / Improve java rest web services frameworks}

Q801. What is the use of !! command ? Can I use it with conjunction to some other string to complete a command ?

Unix

Ans. Its used to execute last command. Yes this can be used with other string to execute new command. For eg - if ls was the last command, We can execute !! -l for having the long listing.

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

_{Like Discuss Correct / Improve unix unix commands !! unix command build management release management}

Q802. What is classpath in a project?

Core Java

Ans. ClassPath is the path where Java looks for class files to resolve the dependencies. For example - If you are using a class "xyz" in your code and have specified the respective import, Where should Java look for the definition of xyz. Java determines using the class path settings.

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

_{Like Discuss Correct / Improve java classpath classpath settings Asked in 2 Companies}

Q803. Why is a constant defined as a static final in Java?

Core Java

Ans. Final makes sure that the value doesn't change after initialization and static makes sure that there is only one copy that can be shared across objects.

Making it non static will unnecessarily create a different copy per object wherein the same value will kept for all copies ( as its final and cannot be changed ).

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

_{Like Discuss Correct / Improve java static final variables variable constants basic frequent}

Q804. Which version control (VC) or software configuration management (SCM) systems work with Merge?

Scm

Ans. You can use Tortoise SVN,which has Merge Utility embedded in it.

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

_{Like Discuss Correct / Improve svn configuration management technologies technical lead}

Q805. .Can you uninstall an older version of Merge before installing a newer version or build?

Ans. NA

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

_{Like Discuss Correct / Improve technologies merge}

Q806. What things you will look for if you get following exception while making DB call ?

table or view does not exist

Database

Ans. First will check if the table or view actually exist in the DB

If it does , Will make sure to see that the application has rights on the schema that holds the respective Table.

Will then make sure that we have prefixed the schema with the table name while accessing it.

Will then make sure that its not DB Cache that's causing it as the table DDL might have been created recently.

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

_{Like Discuss Correct / Improve sql database oracle technical lead}

Q807. What's the benefit for specifying constraints like Not Null , Primary Key explicitly instead of specifying it against the column ?

Database

Ans. In case we specify them explicitly we can have control over constraint name as otherwise they will be system generated. It provides an ease in case we plan to drop the constraint in future.

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

_{Like Discuss Correct / Improve sql database oracle}

Q808. How can we disable a constraint ?

Database

Ans. alter table
table_name
DISABLE constraint
constraint_name;

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

_{Like Discuss Correct / Improve sql database oracle}

Q809. Can we have foreign key reference to a non primary key column ?

Database

Ans. Yes, but the respective key in the foreign table should be declared Unique.

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

_{Like Discuss Correct / Improve sql database oracle Asked in 2 Companies}

Q810. What should be done for auto generating primary key id in a table ?

Database

Ans. We need to create a sequence.

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

_{Like Discuss Correct / Improve sql database oracle}

Q811. Which constraint cannot be specified as an explicit constraint and should be specified with the column only ?

Database

Ans. NOT NULL

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

_{Like Discuss Correct / Improve sql oracle database ddl constraint table creation}

Q812. How can we see Dependencies for the project and where exactly they are defined ?

Maven

Ans. Using

mvn dependency:tree

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

_{Like Discuss Correct / Improve maven maven repository maven dependencies dependency tree}

Q813. What are the benefits of transitive depency in Maven ?

Maven

Ans. Transitive dependencies allows to avoid specifying the libraries that are required by the project which are specified in other dependent projects - Remote or Local.

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

_{Like Discuss Correct / Improve maven maven repository dependencies transitive dependencies build management}

Q814. Will this code compile ?

public class BuggyBread1{
abstract public void test();
}

Core Java

Ans. No. It will give the compilation error saying "The abstract method test in type BuggyBread1 can only be defined by an abstract class".

We need to declare the class abstract for it to have any abstract method.

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

_{Like Discuss Correct / Improve java oops abstract class abstract methods java compilation error}

Q815. Will this Code compile ?

abstract public class BuggyBread1{
abstract public void test(){};
}

Core Java

Ans. No. This will give a compilation error saying "Abstract methods do not specify a body".

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

_{Like Discuss Correct / Improve java abstract classes abstract methods java compilation error java coding java code coding yes-no}

Q816. Give an Example for Builder Pattern ?

Core Java

Ans. String str = new StringBuilder().append("Buggy").append("Bread").toString();

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

_{Like Discuss Correct / Improve java builder pattern design pattern stringbuilder string Asked in 3 Companies}

Try 1 Question(s) Test

Q817. Is this Polymorphism ?

Map<String, List<String>> inventoryManagerCountMap = new HashMap<String, ArrayList<String>>();

Core Java

Ans. No. This will result in compilation error as Polymorphism cannot be performed on Object types.

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

_{Like Discuss Correct / Improve java polymorphism object oriented programming (oops) oops concepts}

Q818. How to know the structure of a Table in Oracle ?

Database

Ans. DESC

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

_{Like Discuss Correct / Improve sql database oracle}

Q819. How to know the constraints on a Table in Oracle ?

Database

Ans. SELECT *
FROM user_constraints
WHERE table_name = ''

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

_{Like Discuss Correct / Improve sql database oracle}

Q820. How to know the default column value of a Table in Oracle ?

Database

Ans. Select DATA_DEFAULT
from DBA_TAB_COLUMNS
where TABLE_NAME = '' and COLUMN_NAME='';

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

_{Like Discuss Correct / Improve sql database oracle}

Search Interview Questions

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