Hello everyone, are you looking for a way to "Compile & Run Java Program Using Command Prompt".. Then this post is for you. While many programming environments will allow you to compile and run a program within the environment, you can also compile and run using Command Prompt. Both Windows and Mac have their own versions of Command Prompt, although it is technically called Terminal on the Mac OS. The process is essentially identical for Windows and Mac. Compiling and Running Save the program. After using a text editor, such as NotePad, to create your Java program, save the program with a .java extension. Of course, the file name can be anything. For the purposes of this tutorial, "filename" will be used as a placeholder for your file name. To ensure that your file is saved as a .java file, be sure to write .java after the file name, and select All Files from the dropdown extension menu. Make note of where you saved the file on your system. Open Command Prompt/Terminal.Accessing the command line differs slightly for Mac and Windows. Windows: Press ⇱ Home, then type cmd. Press ↵ Enter to open the Command Prompt. Mac: In Finder, press the Go tab, select Applications, select Utilities, then select Terminal. Check that Java is installed. Type java -version into your command line. If java is installed, you will see a message stating what version of Java is currently installed. Navigate to the correct folder. Use the command cd followed by the directory name to change your working directory. For example, if you were operating in C:\Users\Bob\Project and wanted to get to C:\Users\Bob\Project\TitanProject, enter in cd TitanProject and press ↵ Enter. You can see a list of what is in your current directory by typing directly and pressing ↵ Enter. Run the program. Enter in java filename and press ↵ Enter . Of course, replace "filename" with whatever the name of your file actually is. After pressing ↵ Enter, your program should run. If you receive an error, or if your program fails to run in any way, refer to the troubleshooting method. Troubleshooting Set your path. If you are running a simple program with all of the files in the same directory, you will probably not need to do this. However, if you are running a more complex program with files in multiple directories, you will need to tell the computer where to look for these files. Windows: Type java -version into the command prompt and press ↵ Enter. Based off the version of Java displayed on the first line, type in set path=%path%;C:\Program Files\Java\jdk1.5.0_09\bin to the command prompt and press ↵ Enter. Substitute jdk1.5.0_09 with whatever version of Java you have installed. Be sure you are entering in this command while in the directory containing your Java project. Mac: Type /usr/libexec/java_home -v 1.7 into the terminal and press ↵. Enter to ensure Java is installed on your system. Then, type echo export "JAVA_HOME=\$(/usr/libexec/java_home)" >> ~/.bash_profile into the terminal and press ↵ Enter. Restart the terminal afterwards. I hope this helps.