How to check java is installed or not || In Windows / Mac / Linux

Checking if Java is installed on your system and determining its version can be done using the command line or terminal. Here’s a step-by-step guide for various operating systems:

Windows

1. Open Command Prompt:

   • Press Win + R, type cmd, and press Enter.

2. Check Java Version:

   • Type the following command and press Enter:

     java -version

   • If Java is installed, you will see output similar to:

If Java is not installed, you will see a message like:

macOS

1. Open Terminal:

   • You can open Terminal from the Applications > Utilities folder or by pressing Command + Space and typing Terminal.

2. Check Java Version:

• Type the following command and press Enter:

          java -version

     If Java is installed, you will see output similar to:

     If Java is not installed, you will see a message prompting you to install Java.

Linux

1. Open Terminal:

   • You can open Terminal from your applications menu or by pressing Ctrl + Alt + T.

2. Check Java Version:

   • Type the following command and press Enter:

             java -version

     If Java is installed, you will see output similar to:

       If Java is not installed, you will see a message like:

Additional Steps (if Java is not installed):

• Windows:

  • Download Java from the official Oracle website.
  • Follow the installation instructions.

• macOS:

  • Download Java from the official Oracle website or use Homebrew:

                   brew install java  

 

• Linux:

Install Java using your package manager. For example, on Ubuntu, you can install OpenJDK with:

         sudo apt update 

         sudo apt install default-jre

        For other distributions, use the equivalent package manager commands.

This guide should help you determine whether Java is installed on your system and how to install it if it is not.