Never used Fortran.
Think of it as an old-style
version of BASIC. WRITE is like
PRINTUSING,
with FORMAT being where you specify the print pattern. Any variable
whose
name starts with the letters I J K L M or N (alphabetic letters
between I
and N (which is the start of "INteger")) is assumed to be an int,
unless
you tell it otherwise. Many brands of it require giving a line
number to
every line.
Oops!
For FORTRAN, that should read, "like some brands of BASIC, you can
skip
assigning line numbers to lines that aren't explicitly referenced."
Strictly speaking, "line numbers" in FORTRAN are actually labels. They
do not have anything to do with line numbering and IIRC they do not have
to appear in an ascending sequence either, they can be assigned randomly
and with arbitrary gaps in the sequence.
Assigning labels ("line numbers") to not explicitly referenced lines in
FORTRAN would be like giving every line a label in assembler, completely
meaningless clutter.
/Jonas