Are annotations necessary in Java?

Annotations are used to provide supplemental information about a program . Annotations start with ‘@’. Annotations do not change the action of a compiled program. Annotations help to associate metadata (information) to the program elements i.e. instance variables, constructors, methods, classes, etc.

In C#, attributes are classes that inherit from the Attribute base class . Any class that inherits from Attribute can be used as a sort of “tag” on other pieces of code. For instance, there is an attribute called ObsoleteAttribute . This is used to signal that code is obsolete and shouldn’t be used anymore.

Annotations in programming languages are, similar to those in linguistics, structural elements containing additional or meta-information in the source code of a program .

In the Java computer programming language, an annotation is a form of syntactic metadata that can be added to Java source code . … Like Javadoc tags, Java annotations can be read from source files. Unlike Javadoc tags, Java annotations can also be embedded in and read from Java class files generated by the Java compiler.