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SET EXACT*
Toggle exact matches for character strings
------------------------------------------------------------------------------
Syntax
SET EXACT on | OFF | <xlToggle>
Arguments
ON enforces exact comparison of character strings including length.
OFF resumes normal character string comparison.
<xlToggle> is a logical expression that must be enclosed in
parentheses. A value of true (.T.) is the same as ON, and a value of
false (.F.) is the same as OFF.
Description
SET EXACT determines how two character strings are compared using the
relational operators (=, >, <, =>, =<). When EXACT is OFF, strings are
compared according to the following rules. assume two character strings
cLeft and cRight where the expression to test is (cLeft = cRight):
. If cRight is a null string (""), return true (.T.).
. If LEN(cRight) is greater than LEN(cLeft), return false (.F.).
. Otherwise, compare all characters in cRight with cLeft. If
all characters in cRight equal cLeft, return true (.T.); otherwise,
return false (.F.).
With EXACT ON, all relational operators except the double equal operator
(==) treat two strings as equal, if they match exactly, excluding
trailing spaces. With the double equal operator (==), all characters in
the string are significant, including trailing spaces.
SET EXACT is a compatibility command and not recommended.
Notes
. Compatibility: In CA-Clipper, unlike other dialects, SET EXACT
has no affect on operations other than relational operators. This
includes the SEEK and FIND commands. If you need to seek exact
matches of character keys, use the example user-defined function
SeekExact() in the SEEK command reference.
Examples
. These examples show various results of the equal operator (=)
with SET EXACT:
SET EXACT OFF
? "123" = "12345" // Result: .F.
? "12345" = "123" // Result: .T.
? "123" = "" // Result: .T.
? "" = "123" // Result: .F.
? "123" = "123 " // Result: .F.
//
SET EXACT ON
? "123" = "12345" // Result: .F.
? "12345" = "123" // Result: .F.
? "123" = "" // Result: .F.
? "" = "123" // Result: .F.
? "123" = "123 " // Result: .T.
Files Library is CLIPPER.LIB.
See Also:
SEEK
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