Question

When writing about methods in Java (e.g. in forums, mailing lists, issue trackers, etc.) many people separate the method name from the class name using the ‘#’ symbol instead of Java’s native . operator; for example, folks refer to Object#toString instead of Object.toString. Where does this syntax come from?

Answer 1

It’s the notation used in javadoc comments when linking to another class’ method.

EDIT

To gather the additional information provided in comments:

• @Hugo notes that the # notation in turn comes from HTML anchors
• @maksimov points out that Object.method is the Java syntax to call static methods, which could be misleading

UPDATE

Java 8 brings a new syntax for method references, which now seems to become more popular – so Object#toString tends to now be written Object::toString.