Java is a programming language that is platform-independent, popular, simple, secure, and statically typed. Before discussing let’s clear Java language needs a runtime platform so before going ahead let’s clear how java is present on the machine.
Java language comprises three components mainly:
Runtime Concepts than only we will check whether Java is there on the Platform (Operating System + Architecture)
1. Java Virtual Machine
This is a machine–specific software which is responsible for byte code on that machine and converts it into machine-specific instructions.
JVM is different for Windows JVM is different for Linux JVM is different for Different Platforms
So as a programmer we don’t need to check presence on the machine as it is pre-installed in the machine. It is responsible for running Java code line by line.
2. Java Runtime Environment
It is simply a package that provides an environment to only run our java code on the machine. No development takes place here because of the absence of developmental tools.
3. Java Development Kit
It is also a package that provides an environment to develop and execute where JRE is a part of it along with developmental tools.
- JDK = JRE + Developmental Tools
- JRE = JVM + Library Classes
Now, The first and Foremost step is to check the Java Development Kit in Windows which is also known as JDK. There are lots of versions of Java. Depending upon the operating system methods there are several methods to find the version of Installed JAVA on your Machine:
Let us discuss 3 standard methods in Windows
- User needs to open Command Prompt and enter- ‘java -version’
- Open control panel and lookup for Java
- Directories method- Click the Menu ‘Start’ and typing About.java or readme file
Taking one by one, showcasing in-depth individually
1. Command Prompt
The CMD (Command Interpreter is a command-line Interface. It supports a set of commands and utilities; and has its own programming language for writing batch files. Open CMD and search java -version. First, we have to an environment variable to the installed path location of the java folder. Otherwise, it will show invalid command. It is called ‘Terminal’ in the case of mac operating systems.
java -version // CMD/Terminal command to check java version on the machine
In the case of Windows OS: It is showing java is installed on the machine with version 1.8.0 (See carefully at line number 5)
“1.8.0_144” is the version of the java
In the case of macOS: It is showing java is installed on the machine with version 14.0.1 ( see carefully at line number 2)
- Open Control Panel and there is an option of the java on the interface of the control panel
- Click on the java option and click about a small pop window will appear
In the case of Windows:
In the case of Mac: Click on the Java icon downside. System preferences in mac are the same as the Control panel in Windows.
Search Program and features in the control panel and search JAVA Named option
In the case of Windows: Simply custom search- About Java
In the case of Mac:
Press the command button followed by a spacebar without lifting fingers from the command button.
A popup box will appear for less than a second followed by another pop-up as shown below:
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