HP 3000 Manuals HP 3000 Manuals
The FORTRAN 77 Character Set
Each language element is written using the letters A to Z, the digits 0
to 9, and the following special characters:
Character Character Name Character Character Name
Blank , Comma
= Equals : Colon
+ Plus ' Apostrophe (single quote)
- Minus
* Asterisk
/ Slash ! Exclamation point 1
( Left parenthesis " Quotation mark 1 (double
quote)
) Right parenthesis % Percent sign 1
. Decimal point & Ampersand 1
$ Dollar sign _ Underscore 1 (break)
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Note:
1. Extension to the ANSI 77 standard.
A tab character (Control-I) in columns 1 to 6 causes blank characters to
be inserted up through column 6. For example, a tab character in column
2 inserts blanks in columns 2 to 6. Elsewhere, except when embedded in a
literal string, a tab is interpreted as a blank character. If a tab
character in column 1 to 6 is followed immediately by a digit from 1 to
9, with blanks or nothing before the tab character, the digit is treated
as a continuation line indicator.
As an extension to the ANSI 77 standard, the 26 lowercase letters (a to
z) are allowed. The compiler considers them identical to their uppercase
equivalents, except in character or Hollerith constants. (Note that this
differs from the C language, in which lowercase letters are distinct from
uppercase letters in identifiers.) Lowercase letters can improve program
readability.
In addition, any printable ASCII character can be used in character and
Hollerith constants, and in comments.
Blanks can be used anywhere within a statement. They are ignored except
in character and Hollerith constants and in compiler directives.