Top 10 Java Questions Asked During Job Interview

Java has been at the heart of all technologies. The programming language is being used by large community of developers across the world. Many of today’s leading technologies use Java at the core. Most tech organizations demand the throughout knowledge of Java for software engineer candidate. Today we have compiled the list of Java questions asked during job interview.





1. What if the main method is declared as private?


Answer: The program compiles properly but at runtime it will give “Main method not public.” message.

2. What is meant by pass by reference and pass by value in Java?

Answer: Pass by reference means, passing the address itself rather than passing the value. Pass by value means passing a copy of the value.

3. If you’re overriding the method equals() of an object, which other method you might also consider?

Answer: hashCode()

4. Why oracle Type 4 driver is named as oracle thin driver?

Answer: Oracle provides a Type 4 JDBC driver, referred to as the Oracle “thin” driver. This driver includes its own implementation of a TCP/IP version of Oracle’s Net8 written entirely in Java, so it is platform independent, can be downloaded to a browser at runtime, and does not require any Oracle software on the client side. This driver requires a TCP/IP listener on the server side, and the client connection string uses the TCP/IP port address, not the TNSNAMES entry for the database name.

5. What is the Java API?

Answer: The Java API is a large collection of ready-made software components that provide many useful capabilities, such as graphical user interface (GUI) widgets.

6. What is the GregorianCalendar class?

Answer: The GregorianCalendar provides support for traditional Western calendars.

7. What is the ResourceBundle class?

Answer: The ResourceBundle class is used to store locale-specific resources that can be loaded by a program to tailor the program’s appearance to the particular locale in which it is being run.

8. Why there are no global variables in Java?

Answer: Global variables are globally accessible. Java does not support globally accessible variables due to following reasons:
The global variables breaks the referential transparency
Global variables create collisions in namespace.

9. What is the SimpleTimeZone class?

Answer: The SimpleTimeZone class provides support for a Gregorian calendar.

10. What is explicit casting?

Answer: Explicit casting in the process in which the complier are specifically informed to about transforming the object.

Source : javacodegeeks.com