Identifier in java

1. Identifiers are names of variables, functions, classes etc. The name used as an identifier must follow the following rules in Java^TM technology.
   
   
   • Each character is either a digit, letter, underscore(_) or currency symbol ($,¢, £ or ¥)
   • First character cannot be a digit.
   • The identifier name must not be a reserved word. 

Note:
Unicode characters above hex 00C0 are allowed as well. Java styling uses initial capital letter on object identifiers, uppercase for constant ids and lowercase for property, method and variable ids.