Implicit Typing Rules

By default, all scalar variables with names beginning with I, J, K, L, M, or N are assumed to be default integer variables. Scalar variables with names beginning with any other letter are assumed to be default real variables. For example:

Names beginning with a dollar sign ($) are implicitly INTEGER.

You can override the default data type implied in a name by specifying data type in either an IMPLICIT statement or a type declaration statement.