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JAVA Identifiers

 JAVA Identifiers  

A name in java program is called identifiers. It may be a class name, method name, variable name, and label name.


class Test

{

      public static void main(string[] args)

     {

           int x = 10;

     }

}

*Text in red color are identifiers.     


Rules to define Java Identifiers:

Rule 1: The only allowed characters in java identifiers are:

          1) a to z

          2) A to Z

          3) 0 to 9

          4) _ (Underscore)

          5) $

Rule 2: If we are using any other character we will get a compile-time error.

         1) total_number   ----------> Valid

         2) Total#              ----------> Invalid

Rule 3: Identifiers are not allowed to starts with digits:

         1) ABC123          -----------> Valid

         2) 123ABC         ------------> Invalid

Rule 4: Java identifiers are case sensitive up course java language itself treated as case sensitive language.

Rule 5: There is no length limit for java identifiers but it is not recommended to take more than 15 lengths.

Rule 6: We can't use reserved words as identifiers.

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