SETEXACT() Short: ------ SETEXACT() Determines if exact is on/off Returns: -------- <lExact> => Exact is on/off Syntax: ------- SETEXACT([lNew]) Description: ------------ Returns current SET EXACT setting and optionally sets exact on/off with [lNew] .t. = ON .f. = OFF Examples: --------- nOldexact = SETEXACT(.f.) // SET EXACT OFF * code SETEXACT(nOldexact) Source: ------- S_SETEX.PRG
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 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
?|?? Display one or more values to the console @...BOX Draw a box on the screen @...CLEAR Clear a rectangular region of the screen @...GET Create a new Get object and display it @...PROMPT Paint a menu item and define a message @...SAY Display data at a specified screen or printer row and column @...TO Draw a single- or double-line box ACCEPT* Place keyboard input into a memory variable APPEND BLANK Add a new record to the current database file APPEND FROM Import records from a database (.dbf) file or ASCII text file AVERAGE Average numeric expressions in the current work area CALL* Execute a C or Assembler procedure CANCEL* Terminate program processing CLEAR ALL* Close files and release public and private variables CLEAR GETS Release Get objects from the current GetList array CLEAR MEMORY Release all public and private variables CLEAR SCREEN Clear the screen and return the cursor home CLEAR TYPEAHEAD Empty the keyboard buffer CLOSE Close a specific set of files COMMIT Perform a solid-disk write for all active work areas CONTINUE Resume a pending LOCATE COPY FILE Copy a file to a new file or to a device COPY STRUCTURE Copy the current .dbf structure to a new database (.dbf) file COPY STRU EXTE Copy field definitions to a .dbf file COPY TO Export records to a database (.dbf) file or ASCII text file COUNT Tally records to a variable CREATE Create an empty structure extended (.dbf) file CREATE FROM Create a new .dbf file from a structure extended file DELETE Mark records for deletion DELETE FILE Remove a file from disk DELETE TAG Delete a tag DIR* Display a listing of files from a specified path DISPLAY Display records to the console EJECT Advance the printhead to top of form ERASE Remove a file from disk FIND* Search an index for a specified key value GO Move the pointer to the specified identity INDEX Create an index file INPUT* Enter the result of an expression into a variable JOIN Create a new database file by merging from two work areas KEYBOARD Stuff a string into the keyboard buffer LABEL FORM Display labels to the console LIST List records to the console LOCATE Search sequentially for a record matching a condition MENU TO Execute a lightbar menu for defined PROMPTs NOTE* Place a single-line comment in a program file PACK Remove deleted records from a database file QUIT Terminate program processing READ Activate full-screen editing mode using Get objects RECALL Restore records marked for deletion REINDEX Rebuild open indexes in the current work area RELEASE Delete public and private memory variables RENAME Change the name of a file REPLACE Assign new values to field variables REPORT FORM Display a report to the console RESTORE Retrieve memory variables from a memory (.mem) file RESTORE SCREEN* Display a saved screen RUN Execute a DOS command or program SAVE Save variables to a memory (.mem) file SAVE SCREEN* Save the current screen to a buffer or variable SEEK Search an order for a specified key value SELECT Change the current work area SET ALTERNATE Echo console output to a text file SET BELL Toggle sounding of the bell during full-screen operations SET CENTURY Modify the date format to include or omit century digits SET COLOR* Define screen colors SET CONFIRM Toggle required exit key to terminate GETs SET CONSOLE Toggle console display to the screen SET CURSOR Toggle the screen cursor on or off SET DATE Set the date format for input and display SET DECIMALS Set the number of decimal places to be displayed SET DEFAULT Set the CA-Clipper default drive and directory SET DELETED Toggle filtering of deleted records SET DELIMITERS Toggle or define GET delimiters SET DESCENDING Change the descending flag of the controlling order SET DEVICE Direct @...SAYs to the screen or printer SET EPOCH Control the interpretation of dates with no century digits SET ESCAPE Toggle Esc as a READ exit key SET EXACT* Toggle exact matches for character strings SET EXCLUSIVE* Establish shared or exclusive USE of database files SET FILTER Hide records not meeting a condition SET FIXED Toggle fixing of the number of decimal digits displayed SET FORMAT* Activate a format when READ is executed SET FUNCTION Assign a character string to a function key SET INDEX Open one or more order bags in the current work area SET INTENSITY Toggle enhanced display of GETs and PROMPTs SET KEY Assign a procedure invocation to a key SET MARGIN Set the page offset for all printed output SET MEMOBLOCK Change the block size for memo files SET MESSAGE Set the @...PROMPT message line row SET OPTIMIZE Change the setting that optimizes using open orders SET ORDER Select the controlling order SET PATH Specify the CA-Clipper search path for opening files SET PRINTER Toggle echo of output to printer or set the print destination SET PROCEDURE* Compile procedures and functions into the current object file SET RELATION Relate two work areas by a key value or record number SET SCOPE Change the boundaries for scoping keys in controlling order SET SCOPEBOTTOM Change bottom boundary for scoping keys in controlling order SET SCOPETOP Change top boundary for scoping keys in controlling order SET SCOREBOARD Toggle the message display from READ or MEMOEDIT() SET SOFTSEEK Toggle relative seeking SET TYPEAHEAD Set the size of the keyboard buffer SET UNIQUE* Toggle inclusion of non-unique keys into an index SET WRAP* Toggle wrapping of the highlight in menus SKIP Move the record pointer to a new position SORT Copy to a database (.dbf) file in sorted order STORE* Assign a value to one or more variables SUM Sum numeric expressions and assign results to variables TEXT* Display a literal block of text TOTAL Summarize records by key value to a database (.dbf) file TYPE Display the contents of a text file UNLOCK Release file/record locks set by the current user UPDATE Update current database file from another database file USE Open an existing database (.dbf) and its associated files WAIT* Suspend program processing until a key is pressed ZAP Remove all records from the current database file
>=
Greater than or equal--binary (Relational)
------------------------------------------------------------------------------
Syntax
<exp1> >= <exp2>
Type
Character, date, logical, memo, numeric
Operands
<exp1> and <exp2> are expressions of any data type to be
compared.
Description
The greater than or equal to operator (>=) is a binary operator that
compares two values of the same data type and returns true (.T.) if
<exp1> is greater than or equal to <exp2>.
. Character: The comparison is based on the underlying ASCII
code. ASCII codes for alphabetic characters are ascending (e.g., the
code for "A" is 65 and the code for "Z" is 90).
. Date: Dates are compared according to the underlying date
value.
. Logical: True (.T.) is greater than false (.F.).
. Memo: Treated the same as character.
. Numeric: Compared based on magnitude.
Examples
. These examples illustrate how the greater than or equal
operator (>=) behaves with different data types:
// Character
? "Z" >= "A" // Result: .T.
? "AZ" >= "A" // Result: .T.
? "A" >= "AZ" // Result: .F.
// Date
? CTOD("12/12/88") >= ;
CTOD("12/11/88") // Result: .T.
// Logical
? .T. >= .F. // Result: .T.
// Numeric
? 2 >= 1 // Result: .T.
? 1 >= 2 // Result: .F.
? 2 >= 2 // Result: .T.
See Also: $ < <= <> = (equality) == >
>
Greater than--binary (Relational)
------------------------------------------------------------------------------
Syntax
<exp1> > <exp2>
Type
Character, date, logical, memo, numeric
Operands
<exp1> and <exp2> are expressions of any type to be compared.
Description
The greater than (>) operator compares two values of the same data type
and returns true (.T.) if <exp1> is greater than <exp2>.
. Character: The comparison is based on the underlying ASCII
code. ASCII codes for alphabetic characters are ascending (e.g., the
code for "A" is 65 and the code for "Z" is 90).
. Date: Dates are compared according to the underlying date
value.
. Logical: True (.T.) is greater than false (.F.).
. Memo: Treated the same as character.
. Numeric: Compared based on magnitude.
Examples
. These examples illustrate how the greater than operator (>)
behaves with different data types:
// Character
? "Z" > "A" // Result: .T.
? "AZ" > "A" // Result: .F.
? "A" > "AZ" // Result: .F.
// Date
? CTOD("12/12/88") > ;
CTOD("12/11/88") // Result: .T.
// Logical
? .T. > .F. // Result: .T.
// Numeric
? 2 > 1 // Result: .T.
? 1 > 2 // Result: .F.
See Also: $ < <= <> = (equality) == >=
==
Exactly equal--binary (Relational)
------------------------------------------------------------------------------
Syntax
<exp1> == <exp2>
Type
All
Operands
<exp1> and <exp2> are expressions of the same data type to be
compared.
Description
The exactly equal operator (==) is a binary operator that compares two
values of the same data type for exact equality depending on the data
type. It returns true (.T.) if <exp1> is equal to <exp2> according to
the following rules:
. Array: Compares for identity. If <exp1> and <exp2> are
variable references to the same array, returns true (.T.); otherwise,
returns
false (.F.).
. Character: Comparison is based on the underlying ASCII code.
ASCII codes for alphabetic characters are ascending (e.g., the code
for "A" is 65 and the code for "Z" is 90). Unlike the relational
equality operator (=) , true (.T.) is returned if <exp1> and <exp2>
are exactly equal including trailing spaces; otherwise, the
comparison returns false (.F.). SET EXACT has no effect.
. Date: Dates are compared according to the underlying date
value; behaves the same as the relational equality operator (=).
. Logical: True (.T.) is exactly equal to true (.T.), and false
(.F.) is exactly equal to false (.F.).
. Memo: Treated the same as character.
. NIL: True (.T.) if compared to a NIL value; false (.F.) if
compared to a value of any other data type.
. Numeric: Compared based on magnitude; behaves the same as the
relational equality operator (=).
. Object: Treated the same as array.
Examples
. These examples illustrate how the == operator behaves with
different data types:
// Character
? "A" == "A" // Result: .T.
? "Z" == "A" // Result: .F.
? "A" == "A " // Result: .F.
? "AA" == "A" // Result: .F.
// Array or object
aOne := { 1, 2, 3 }
aTwo := { 1, 2, 3 }
aThree := aOne
? aOne == aTwo // Result: .F.
// values within the arrays are equal, but the arrays,
// themselves, are separate and distinct
? aOne == aThree // Result: .T.
See Also: $ < <= <> = (equality) > >=
= (equality)
Equal--binary (Relational)
------------------------------------------------------------------------------
Syntax
<exp1> = <exp2>
Type
Character, date, logical, memo, NIL, numeric
Operands
<exp1> and <exp2> are expressions of the same data type to
compare.
Description
The equal operator (= ) compares two values of the same data type and
returns true (.T.) if <exp1> is equal to <exp2> according to the
following rules:
. Character: The comparison is based on the underlying ASCII
code. ASCII codes for alphabetic characters are ascending (e.g., the
code for "A" is 65 and the code for "Z" is 90).
When EXACT is OFF, two character 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 null, returns true (.T.).
- If LEN(cRight) is greater than LEN(cLeft), returns false
(.F.).
- Compare all characters in cRight with cLeft. If all
characters in cRight equal cLeft, returns true (.T.); otherwise,
returns false (.F.).
With EXACT ON, two strings must match exactly except for trailing
blanks.
. Date: Dates are compared according to the underlying date
value.
. Logical: True (.T.) is equal to true (.T.) and false (.F.)
equal to false (.F.).
. Memo: Treated the same as character.
. NIL: True (.T.) if compared to a NIL value; false (.F.) if
compared to a value of any other data type.
. Numeric: Compared based on magnitude.
Examples
. These examples illustrate how the equal operator (=) behaves
with different data types:
// Character
SET EXACT ON
? "123" = "123 " // Result: .T.
? " 123" = "123" // Result: .F.
SET EXACT OFF
? "123" = "12345" // Result: .F.
? "12345" = "123" // Result: .T.
? "123" = "" // Result: .T.
? "" = "123" // Result: .F.
// Date
? CTOD("12/12/88") = ;
CTOD("12/12/88") // Result: .T.
// Logical
? .T. = .T. // Result: .T.
? .F. = .T. // Result: .F.
// NIL
? NIL = NIL // Result: .T.
? NIL = 12 // Result: .F.
? NIL = CTOD("") // Result: .F.
// Numeric
? 2 = 1 // Result: .F.
? 1 = 1 // Result: .T.
See Also: $ < <= <> == > >=
<> != #
Not equal--binary (Relational)
------------------------------------------------------------------------------
Syntax
<exp1> <> <exp2>
<exp1> != <exp2>
<exp1> # <exp2>
Type
Character, date, logical, memo, NIL, numeric
Operands
<exp1> and <exp2> are expressions of the same data type or NIL
to be compared for inequality.
Description
The not equal ( <>) operator compares two values of the same data type
and returns true (.T.) if <exp1> is not equal to <exp2> according to the
following rules:
. Character: The comparison is based on the underlying ASCII
code and is the inverse of the equal operator (=). This means that
the comparison is sensitive to the current EXACT SETting. See the
examples below.
. Date: Dates are compared according to the underlying date
value.
. Logical: False (.F.) is not equal to true (.T.).
. Memo: Treated the same as character.
. NIL: All values compared to NIL other than NIL return true
(.T.).
. Numeric: Compared based on magnitude.
Examples
. These examples illustrate how the not equal operator (<>)
behaves with different data types:
// Character
SET EXACT ON
? "123" <> "12345" // Result: .T.
? "12345" <> "123" // Result: .T.
? "123" <> "" // Result: .T.
? "" <> "123" // Result: .T.
SET EXACT OFF
? "123" <> "12345" // Result: .T.
? "12345" <> "123" // Result: .F.
? "123" <> "" // Result: .F.
? "" <> "123" // Result: .T.
// Date
? CTOD("12/12/88") <> ;
CTOD("12/12/88") // Result: .F.
// Logical
? .T. <> .T. // Result: .F.
? .T. <> .F. // Result: .T.
// NIL
? NIL <> NIL // Result: .F.
? NIL <> 12 // Result: .T.
? NIL <> "hello" // Result: .T.
// Numeric
? 2 <> 1 // Result: .T.
? 1 <> 1 // Result: .F.
See Also: $ < <= = (equality) == > >=
