JAVA

JAVA

Java is a popular and powerful programming language, created in 1995.

It is owned by Oracle, and more than 3 billion devices run Java.

It is high level programming language.

It also statically type programming language.

It is used for develop web applications desktop applications and games etc..,

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Why Use Java?

Java works on different platforms (Windows, Mac, Linux, Raspberry Pi, etc.)
It is one of the most popular programming languages in the world
It has a large demand in the current job market
It is easy to learn and simple to use
It is open-source and free
It is secure, fast and powerful

What is JDK?

JDK stand for java development kit

It is used to build and develop the java program

It internally contains JRE

It contains the compiler and debugger

It contains all the related set of libraries and files to build and compile the java program

Without JDK we cant build any java program

What is JRE?

JRE stands for Java Runtime environment

JRE is the responsible unit to run the java program

Without JRE we cant run java program (JDK is used to build java program, where as JRE is used to run java program. Such that without JDK, I mean with only JRE we can run the java program even without JDK)

JRE contains JVM

JRE contains all the inbuilt packages and library files (lang, io, util etc all packages are present in JRE)

What is JVM?

JVM stands for Java Virtual Machine

JVM is platform dependent

JVM takes .class files and executes it by managing the memory (JVM architecture is attached in other slide, for more reference)

JVM contains JIT

JVM loads, verifies and executes the code and provides the runtime environment

JVM plays a major role in java memory management

What is JIT?

JIT stands for Just In Time compiler

Java was a interpreted programming language, but after introducing JIT it was called as interpreted-compiled programming language

JIT increased the speed of execution

JIT helps the JVM to find the active OS

JIT was introduced from 1.2 JDK

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