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 Toggle exact matches for character strings

     SET EXACT on | OFF | <xlToggle>


     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.


     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.


     .  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.


     .  These examples show various results of the equal operator (=)
        with SET EXACT:

        ? "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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