Java is a programming language that is widely used for developing cross-platform applications. The simplest way to run a Java program is by using an integrated development environment (IDE) such as Eclipse, IntelliJ, or NetBeans. However, sometimes you may need to run a Java program from the command prompt for various reasons, such as testing or debugging purposes.

Here, we will explain how to run a Java program from the command prompt step by step.

Step 1: Write the Java code

Before running a Java program through the command prompt, you need to write the code first. You can use any text editor to write the Java code, such as Notepad or Sublime Text. Select the file name extension as .java.

Step 2: Compile the Java code

Once you have written the Java code, you need to compile it. The Java compiler converts the code into bytecode which is then executed by the Java Virtual Machine (JVM). Open the command prompt and navigate to the directory where the source code is saved. Then type the following command to compile the Java code into bytecode.

`javac filename.java`

This command will generate a file called `filename.class` in the same directory.

Step 3: Run the Java program

Now, you are ready to run the Java program from the command prompt. Use the following command to run the program:

`java filename`

Where filename is the name of the Java class that contains the main method. If your Java class is in a package, include the package name with a period separation. For example, if your Java class is in the package `com.company`, use the following command to run the program:

`java com.company.filename`

Step 4: View the output

Once you run the Java program through the command prompt, you should be able to see the output on the console. You can use System.out.println(“…”) statements to print output to the console.

Conclusion, running a Java Program from the Command Prompt is straightforward, but it requires a few steps. To do that, you need to write code in a text editor, compile the code using the javac command, and then run the code using the java command. The command prompt method can be tedious, but it’s an essential skill to have as a Java programmer. Knowing how to run a Java program from the command line is crucial for debugging and testing.