What is the difference between JVM, JDK & JRE

JVM

The Java Virtual machine (JVM) is the virtual machine that run the Java bytecodes. The JVM doesn't understand Java typo, that's why you compile your *.java files to obtain *.class files that contain the bytecodes understandable by the JVM. It's also the entity that allows Java to be a "portable language" (write once, run anywhere). Indeed there are specific implementations of the JVM for different systems (Windows, Linux, MacOS, ..), the aim is that with the same bytecodes they all give the same results.

JRE

Java Runtime Environment (JRE) The Java Runtime Environment (JRE) provides the libraries, the Java Virtual Machine, and other components to run applets and applications written in the Java programming language. In addition, two key deployment technologies are part of the JRE: Java Plug-in, which enables applets to run in popular browsers; and Java Web Start, which deploys standalone applications over a network. It is also the foundation for the technologies in the Java 2 Platform, Enterprise Edition (J2EE) for enterprise software development and deployment. The JRE does not contain tools and utilities such as compilers or debuggers for developing applets and applications.

JDK

Java Development Kit (JDK) The JDK is a superset of the JRE, and contains everything that is in the JRE, plus tools such as the compilers and debuggers necessary for developing applets and applications.

Simply:

JDK (Java Development Kit) :

contains tools needed to develop the Java programs.
You need JDK, if at all you want to write your own programs, and to compile them.

JRE (Java Runtime Environment) :

Java Runtime Environment contains JVM, class libraries, and other supporting files. JRE is targeted for execution of Java files.

JVM (Java Virtual Machine) :

The JVM interprets the byte code into the machine code depending upon the underlying operating system and hardware combination. It is responsible for all the things like garbage collection, array bounds checking, etc… Java Virtual Machine provides a platform-independent way of executing code.

Also Read :

1. Installing Java 7 on Ubuntu

2. Why we Pass String array as argument to main method in Java

Comments

ജാവാ വളരെ സിമ്പിൾ ആണ് , പവർഫുൾ ഭയങ്കര പവർഫുൾ ആണ്.

ജാവ യെ കുറിച്ച് മലയാളത്തിൽ ഡോകുമെന്റുകളോ ബ്ലോഗ്‌കളോ കൂടുതൽ ഇല്ലാത്തതുകൊണ്ട് എനികറിയവുന്നത് ഷെയർ ചെയ്യാം എന്ന് വിചാരിച്ചു . ജവയെ കുറിച്ച് പറയുകയാണെങ്കിൽ ജാവാ വളരെ സിമ്പിൾ ആണ് , പവർഫുൾ ഭയങ്കര പവർഫുൾ ആണ്. :) 1. നമ്മടെ Sun MicroSystems 1995 ൽ തുടങ്ങി വച്ചാ സംഭവമാണിത് . 2. ഇപ്പൊ ജാവയുടെ എട്ടാമത്തെ വെർഷൻ വരെ ഇറങ്ങികഴിഞ്ഞു . ജാവയുടെ തിയറിയെ കുറിച്ച് എനിക്ക് പറയാൻ താല്പര്യം ഇല്ലാ, അത് അറിവിള്ളവർ നല്ലപോലെ പറഞ്ഞിടുണ്ട്. നമുക്ക് ഡയറക്റ്റ് ആയി കോഡിംഗ് പാർട്ടിലേക്ക് പോകാം. എങ്ങനെയാ ജാവ ഇൻസ്റ്റോൾ ചെയണ്ടേ എന്നൊക്കെ ഒന്ന് ഗൂഗിൾനോട് ചോദിച്ചാ മതി പുള്ളി പറഞ്ഞുതരും. പിന്നെ എല്ലാവരും പറയുന്നു ജാവാ Object Oriented ആണെന്ന് . അതെ ജാവാ Object Oriented ആണ് . എന്താണ് Object ?, Object നു വച്ചാ ഒരു സാധനം അത്രതന്നെ. ഇപ്പൊ example പറയുകയാണെങ്കിൽ Book ഒരു സാധനമാണ് . Book റ്റെ പ്രതേകത എന്തൊക്കെ അന്നെന്നുവച്ചാ ആതിനൊരു Auther ഉണ്ടാകും, അതൊരു Category ൽ പെട്ട book ആയിരിക്കും (Novel / Academic ) പിന്നെ ഓരോ bookനും അ...

Angular (web framework)

Angular is a TypeScript-based free and open-source web application framework lead by the Angular Team at Google and by a community of individuals and corporations. Angular is a complete rewrite from the same team that built AngularJS. Google designed Angular as a ground-up rewrite of AngularJS. Angular 14 was released on June 02, 2022. Some new features include typed forms, standalone components, and new primitives in the Angular CDK (component dev kit). All the major releases are supported for 18 months. This consists of 6 months of active support, during which regularly-scheduled updates and patches are released. It is then followed by 12 months of long-term support (LTS), during which only critical fixes and security patches are released. Official website :- https://angular.io/

Java String Token

Problem Given a string, find number of words in that string. For this problem a word is defined by a string of one or more english alphabets. Input Format A string not more than 400000 characters long. The string can be defined by following regular expression: [A-Za-z !,?.\_'@]+ That means the string will only contain english alphabets, blank spaces and this characters: "!,?._'@". Output Format In the first line, print number of words nn in the string. The words don't need to be unique. In the next nn lines, print all the words you found in the order they appeared in the input. Sample Input He is a very very good boy, isn't he? Sample Output 10 He is a very very good boy isn t he Solution import java.io.* ; import java.util.* ; public class Solution { ...

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