How to Compile a Java Program

This updated guide examines How to Compile a Java Program and organizes the essential facts, background, and practical takeaways in clear American English.

Method 1

Using Java Software Development Kit

1. Open the command prompt. You can use the Java Software Development Kit (Java SDK) from the command prompt on Windows, macOS, or Linux. If you don't have the Java SDK installed, see How to Install the Java Software Development Kit. Here's how to get to the command prompt on each system:
   • Windows: Right-click the Start menu and select Command Prompt . If you don't see this option, typecmdinto the Windows Search bar and click Command Prompt in the search results.
   • macOS: Click the magnifying glass at the top-right corner of the screen to open Spotlight, typeterminal, and then click Terminal in the search results.
   • Linux: PressCtrl+Alt+T.
2. Use thecdcommand to access the directory with your Java code. The source code is the file that ends with the.javafile extension.
3. Typejavac sourcecode.java and press?Enteror?Return. Replace sourcecode.java with the name of your source file.^{[1]XResearch source}This compiles your source code into an executable file, which ends with the.classextension.
   • To see the name of the new file in the current directory, run thedir(Windows) orls -a(Mac/Linux) command.
   • If you see an error when trying to
4. Typejava programname and press?Enteror?Return. Replace programname with the name of your program. This runs the program at the command line.

Method 2

Using an Online Java Compiler

1. Navigate tohttps://www.codiva.ioin a web browser. Codiva is an online Java compiler that's great for people who can't install a compiler locally—it can even be used on a phone or tablet.
   • There are a variety of online compilers out there if Codiva doesn't work for your needs. Some other popular options are Jdoodle, and OnlineGDB.
2. Sign in or create an account. If you're new to Codiva, click Create Account at the top-right corner to sign up.
3. Enter a project name and clickCreate. This creates a new project, which is like a container for your source files.^{[2]XResearch source}
4. Create a Java source file and clickCreate. Java source files must end with the.javafile extension. The new file will appear in project's tree, which appears in the right panel.
   • For example, if you're creating a Java program called HelloWorld, name the source fileHelloWorld.java.
5. Write or paste your code into the editor. The code will compile in the background as you type. Additionally, it will display any code errors as they occur.
6. ClickRunto run the program. Since the code compiles automatically, clicking Run will just launch your app in its current state.