2.3 Comments

Java supports three types of comments:

• A standard C-style comment that begins with /* and continues until the next */. As in most implementations of C, this style of comment cannot be nested.

• A C++-style comment that begins with // and continues until the end of the line.

• A special "doc comment" that begins with /** and continues until the next */. These comments may not be nested. Doc comments are specially processed by the javadoc program to produce simple online documentation from the Java source code. See Chapter 13, Java Syntax for more information on the doc comment syntax, and Chapter 16, JDK Tools for more information on the javadoc program.

Since C-style comments do not nest, it is a good idea to use C++-style // comments for most of your short comments within method bodies. This allows you to use /* */ comments to comment out large blocks of code when you need to do that during development. This is especially important because, as you will see, Java does not support a preprocessor that allows you to use #if 0 to comment out a block.