| Discussion:
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The PREV function returns the value of the key immediately
previous to the current file pointer file attached to the
specified logical unit number. This feature provides a method for
a program to read backwards through a keyed file. (See the
FILE
statement for another method to read backwards through a keyed
file.)
The PREV function does not move the record pointer in the file.
To move the record pointer, you must use input/output statements
such as
READ and WRITE.
Other file-related functions:
FIRST,
KEY,
LAST.
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