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Identifiers

                 An identifier is the name given to an object in a Java program. It is used to uniquely identify an
                 object in a program, such as, a class name or a method name.
                 Rules for Naming Identifiers


                 The rules for naming identifiers are:
                    Can consist of letters, digits 0–9, underscore ( _ ), and dollar ($) sign.

                    Cannot start with a digit.

                    Keywords cannot be used.
                    No special symbols like !, @, #, %, etc. can be used.

                    Identifiers are case-sensitive, which means ‘name’ and ‘NAME’ are two different identifiers.

                 Examples of some valid identifier names are Employee123, mygood_book, _address93, FirstName,
                 age, etc.

                 Examples of some invalid identifier names are 1_Name, @Address, 1234, –Age, etc.
                 Keywords

                 Keywords are reserved words that cannot be used as identifiers because they have a special
                 meaning for the Java compiler. Some of the Java keywords are given below:

                                                           Java Keywords

                 abstract             class               final               interface           static
                 assert               const               float               long                switch
                 boolean              continue            for                 new                 this

                 break                default             if                  private             throw
                 byte                 do                  implements          protected           throws

                 case                 double              import              public              try
                 catch                else                instanceof          return              void

                 char                 extends             int                 short               while

                 Although reserved as a keyword in Java, const is not used and has no function.

                 Additionally, there are three more reserved words in Java: true, false, and null. Technically, these
                 are literal values rather than keywords. However, they cannot be used as identifiers and have

                 specific meanings for the Java compiler.





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