Names

In Fortran 90, names denote entities such as variables, procedures, derived types, named constants, and COMMON blocks. A name must start with a letter but can consist of any combination of letters, digits, and underscore (_) characters. As an extension in HP Fortran, the dollar sign may also be used in a name, but not as the first character.

The Fortran 90 Standard allows a maximum length of 31 characters in a name. In HP Fortran this limit is extended to 255 characters, and all are significant—that is, two names that differ only in their 255th character are treated as distinct. Names and keywords are case insensitive: for example, Title$23_Name and TITLE$23_NAME are the same name.

The CASE, IF, and DO constructs can optionally be given names. The construct name appears before the first statement of the construct, followed by a colon (:). The same name must appear at the end of the final statement of the construct. For more information about these constructs, refer to “Control constructs and statement blocks”.