java Identifiers
The names which can be used for classes name, variables and methods name are called identifiers. There are some rule which must be followed: All identifiers should begin with a letter (A to Z or a to z), dolor sign ($) or an underscore (_). After the first character identifiers can have any combination of characters. A keyword / reserved words cannot be used as an identifier. Identifiers are case sensitive, so Name and name are two different identifiers. The identifier can’t be start from numeric such as 123…n.