What are Identifiers and Constants in C++?

Identifier and Constant:

Identifier refers to the name of the variables.   The variable may be a array,  function, primary data type, class, etc. There are rules to name an identifier.

·     variable  or Identifier name must start with alphabet or underscore

·     Identifier must be alphabet, number, and underscore. An identifier must not have following character   %,#,<,>, $,etc.

·     Identifier is case sensitive

·     Keyword cannot be an identifier

·     Identifier has not limit to its length