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The character type is unique in that each character item has a length
defined for it: this is the number of characters that it holds. In
general the length is fixed when the item is declared and cannot be
altered during execution. The only exception to this is for dummy
arguments of procedures: here it is possible for the dummy argument to
acquire the length of the corresponding actual argument. Using this
facility, general-purpose procedures can be written to operate on
character strings irrespective of their length. In addition, the rules
for character assignment take care of mismatched lengths by truncating or
padding with blanks on the right as necessary. This means that the
Fortran character type has many of the properties of a genuine
variable-length character-handling system.
The maximum length of a character item is system-dependent: it is
safe to assume that all systems will allow strings of up to 255
characters, a length limit of 32767 (or even more) is quite
common. The minimum length of a character item is one
character; empty or null strings are not permitted.
Helen Rowlands
8/27/1998