How to Write Comments in Java

In Brief...

A comment in a Java program is one or more lines of text. A comment may be single line, multi-line or Javadoc. To practice writing each type of comment, follow these four steps.


  1. Open your text editor and create a new file. Type in the following Java statements. Observe the three types of comments and the examples of each type.
    Java Source for Block of Code

  2. Save your file as

  3. Open a command prompt and navigate to the directory containing your new Java program. Then type in the command to compile your program and hit Enter.
    Compile Program with Block

  4. Now you will run your Java program. Type in the command to run the Java runtime launcher and hit Enter. Notice the output from the block of code you wrote in the Java class.
    Run Program with Block

Author: Stephen Withrow

Stephen has over 30 years' experience in training, development, and consulting in a variety of technology areas including Java, C, C++, XML, JavaScript, AJAX, Tomcat, JBoss, Oracle, and DB2. His background includes design and implementation of business solutions on client/server, Web, and enterprise platforms. Stephen is a published writer in both technical and non-technical endeavors. Stephen received an undergraduate degree in Computer Science and Physics from Florida State University.