Important topics in core java for interview

Posted by tib on October 26th, 2019

What is Java?

Java is a programing language and a platform.

Java is a high level, robust, object-oriented and secure programing language.

Platform: Any hardware or code environment within which a program runs, is understood as a platform. Since Java has a runtime environment (JRE) and API, it's known as a platform.

Important topics in core java for interview

Are you the one who has set to be told java however don’t grasp

  • Where to start?
  • What java books to follow?
  • about necessary topics to hide in java
  • about on-line free materials for learning java
  • about on-line paid courses

This article goes to assist you with everything that you simply have to be compelled to grasp to go begin your java journey from beginner to skilled.

Here we'll tell about:

  • the necessary topics to be told in core java,
  • java books to follow,
  • java on-line free courses,
  • java on-line paid courses

Our initial move ought to be to be told the necessary topics which will be useful in building sensible comes.

 For details: Core java Training in Marathahalli

Important topics in core java

Given below are the important topics that you should cover to get well acquainted and begin working on java technologies.

Basic of java

  • class and objects
  • java data types,
  • java variables (class variable, instance variable, local variable, parameter variables)
  • Why java is platform independence?
  • jdk, jre, jvm,
  • bytecode, path, classpath
  • Public static void main (String [] args) → Explain the significance of each words in it.
  • java method
  • java constructor
  • java program internal working
  • java vs javac command
  • Also learn few basic programs (click the link for programs)

Decision making statements

  • if,
  • if-else,
  • if-else-if, and
  • switch statement
  • Basic programs on decision making

Loop controls

  • for loop,
  • while loop
  • do-while loop
  • break and continue
  • enhanced for loop
  • Loop control programs

Object Oriented Programming concepts

  • Polymorphism → Overloading and Overriding
  • Encapsulation → How to achieve encapsulation?
  • Abstraction → Ways to achieve partial and complete abstraction using abstract class/interface
  • Inheritance → Different types of inheritance
  • Why multiple inheritance not supported by java classes? Core java Training in Bangalore

Java Strings

  • ways to create string objects
  • Why string is immutable?
  • == vs equals
  • string buffer, string builder and their difference
  • a split method, String tokenizer
  • Various methods of String like length, substring, concat, tochararray, toupper, tolower, etc.

Collection interface and classes

  • Lists like Arraylist, Linkedlist, Vector and difference between them
  • Sets like Hashset, LinkedHashSet, TreeSet and differences between them
  • Maps like HashMap, LinkedHashMap, TreeMap and differences between them
  • List vs Set vs Map
  • Collection vs Collections
  • Hashtable and hashing technique
  • hashcode and equals contract
  • Using different Collection, storing elements in them, fetching elements, sorting and searching elements.

Generics in java

  • advantages of using generics
  • How to use generics in java program?

Exception handling mechanism

  • exception vs error
  • exception hierarchy and what is parent class of all exception
  • try-catch
  • finally
  • the correct sequential order of java try with multiple catch and a finally
  • checked vs unchecked exception
  • throw, throws and their difference
  • custom exception

Multithreading concepts

  • ways of creating java thread
  • thread life cycle
  • methods like sleep, wait, notify, notifyall
  • synchronization
  • deadlock

Date-time concepts in java

  • DateFormat
  • SimpleDateFormat
  • convert from String to Date
  • convert from Date to String
  • convert java.util.Date to java.sql.Date


  • Establishing jdbc connection
  • different statements like statement, prepared statement, callable statement
  • Important keywords
  • super,
  • this,
  • final,
  • finally,
  • finalize,
  • static

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Joined: April 4th, 2019
Articles Posted: 35

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