TABLE OF CONTENTS In this appendix we provide a brief introduction to the features of Fortran 90 (and one from the newer standard, Fortran 95) that are relevant to understanding the material in this book. This represents only a small subset of the properties of the language. Interested readers may wish to consult one of the references described in the "" at the end of this appendix to read more about the language.
Fortran 90 introduced a new lexical input format called free source form, in which the old column-oriented form is replaced by a line-oriented form that permits multiple statements on a line. Since this book uses free source form exclusively, we concentrate on those features that are most relevant to understanding the text.
As in the old format, statements are assumed to be ended by the end of a line. However, if the line contains an ampersand (&) not in a comment, the statement continues on the next line. If a keyword or character string is split across lines, an ampersand must begin the continuing line as well.
Multiple statements can appear on a line, separated by semicolons (;). The last statement before the end of a line need not be terminated by a semicolon.
The exclamation point (!) is used to begin a comment if it appears outside a quoted string or another comment.
Blanks are significant and may not appear inside a keyword, name, or number. The exception is a keyword that is really a...
