Java Interview Questions || Coding Tag

1
JAVA Interview Questions

• By Coding Tag

2
About Us
About Coding Tag Coding Tag is the E-learning
website covering all tutorials of technical and
nontechnical tutorials including advanced
programming , web Development,current affairs and
Technical interviews.... In Coding tag , Its
the outstanding reference platform for Interview
questions as well on - CSS HTML PHP SQL C C
OOPS Ajax JS Python etc...
In this presentation you will learn about latest
frequently asked Interview questions related to
Java and Advance Java. More info related to Java
Interview questions
2
3
What are the features in Java?

• Java Programming Language is a lot more than just
  a usual programming language It is also a
  multi-platform,which is with inbuilt security to
  prevent hacking
• Here are some features that make java different
  from other languages
• Robustness nature
• Platform Independency
• Global operative
• No Explicit memory management

4
Name some of the Java IDEs.

• IDE stands for Integrated Development Environment
  
• It is an environment that have a lot of classes
  functions in a single package i.e code editor,
  compiler, debugger etc
• Some IDEs are
• NetBeans
• Eclipse
• Intellij IDEA
• DrJava

5
What is the difference between Hashmap and
Hashtable.

• HashMap
• No synchronization of methods
• Iterator is used to iterate the values
• There is no thread safety
• HashMap extends an abstract class Abstract Map
• Allows null key only once and multiple null
  values

• HashTable
• Key methods are synchronization
• Nothing with null attribute is allowed
• Thread safety
• The Enumerator is used to iterate the values
• Slower performances

6
How to read text from Inputstream in Java?

• Java provides several mechanisms in order to read
  from a file. One important class that helps in
  performing this operation is the BufferedReader.
• BufferedReader is a Java class that reads text
  from the input stream. It buffers the characters
  so that it can get the efficient reading of
  characters, arrays, etc. It inherits the reader
  class and makes the code efficient since we can
  read the data line-by-line with the readline()
  method
• public static void main(String args throws
  Exception)
• FileReader f new FileReader("file location")
• BufferedReader b new BufferedReader(f)
• while((int i b.read()) ! -1)
• System.out.println((char) i)
• b.close() f.close()

7
Difference between Scanner and BufferedReader.

• BufferedReader
• Synchronous and should be used with multiple
  threads
• Buffer Memory is large
• Faster than scanner
• Uses buffering to read characters from the
  character input stream

• Scanner
• Not synchronous and not used with multiple
  threads
• Buffer Memory is smaller
• Does parsing of the input data
• It is a simple text scanner ,parses strings and
  primitive types

8
What is Linked list in Java?

• In java Linked list class is a doubly linked list
  implementation of list and Deque interfaces.
• Linked list Class Declaration,
• Linked list is a generic class that has this
  declaration
• Public class LinkedListltEgt
• Extends AbstractSequentialListltEgt
• Implements ListltEgt, DequeltEgt ,CloneableltEgt

9
Thanks!

• Any questions? You can find me at codingtag.com