Core Java (All)

Java Core - Additional Important Concepts for Exams and Interviews

Submitted by heartin on Tue, 09/21/2021 - 01:36

Important concepts that can help you with core Java interviews and exams.

Java Version History

Submitted by sneha on Wed, 05/13/2020 - 23:35

Like in movies, going through some flash back through the history can help us understand the present better.

  • JDK Beta – 1995

  • JDK 1.0 – January 1996

  • JDK 1.1 – February 1997

  • J2SE 1.2 – December 1998

  • J2SE 1.3 – May 2000

  • J2SE 1.4 – February 2002

  • J2SE 5.0 – September 2004

  • Java SE 6 – December 2006

  • Java SE 7 – July 2011

  • Java SE 8 – March 2014

  • Java SE 9 – September 2017

Main Method in Java

Submitted by heartin on Sat, 10/25/2014 - 22:16

The main method is the entry point to a desktop based core Java application.

Previously, we created our first Java program "Hello.java" as:

public class Hello {

  public static void main(String[] args)

  {

     System.out.println("Hello");

  }

}

We then compiled it using javac as:

javac Hello.java 

We then executed it as:

java Hello

And output should be:

Hello

String Interning and Performance Tuning in Java

Submitted by heartin on Wed, 08/06/2014 - 10:45

String interning is a method of storing only one copy of each distinct string value. Strings in Java are immutable and hence this sharing is perfectly safe and give you better performance. The distinct values are stored in a fixed-size hashtable usually referred to as string intern pool or string pool. The single copy of each string is called its 'intern'. You can read more about the basics of String interning with examples @ string-interning-in-java-with-examples.

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