Converts a character expression representing
a single character into the corresponding ASCII (or internal code
page) value, returned as an INTEGER.
Syntax
ASC ( expression
[ , target-codepage [ , source-codepage ] ] )
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expression
- An expression with a value of a single character that you want
to convert to an ASCII (or internal code page) integer value. If expression is
a constant, you must enclose it in quotation marks (" "). If the
value of expression is other than a single character,
ASC returns the value -1.
The values for expression are
case sensitive. For example, ASC("a") returns a different value
than ASC("A").
-
target-codepage
- A character-string expression that evaluates to the name of
a code page. The name that you specify must be a valid code page
name available in the OpenEdge-install-dir/convmap.cp file
(a binary file that contains all of the tables that ABL uses for character
management). If you supply a non-valid name, the ASC function returns
the value -1 and returns a runtime error. Before returning an integer
value, the ASC function converts expression from source-codepage to target-codepage.
The returned integer value is relative to target-codepage.
If you do not specify target-codepage, the value
returned is the code page identified with the Internal Code Page (-cpinternal)
parameter.
-
source-codepage
- A character-string expression that evaluates to the name of
a code page. The name that you specify must be a valid code page
name available in the OpenEdge-install-dir/convmap.cp file.
If you supply a non-valid name, the ASC function returns the value
-1. The source-codepage specifies the name of
the code page to which expression is relative.
The default value of source-codepage is the code
page identified with the Internal Code Page (-cpinternal) parameter.
Example
The
following procedure counts how many customers names begin with each
of the letters, A-Z. It counts all other customers separately. The
procedure uses the ASC function to translate a letter into an integer
that it uses as an array subscript for counting.
r-asc.p
DEFINE VARIABLE ix AS INTEGER NO-UNDO.
DEFINE VARIABLE jx AS INTEGER NO-UNDO.
DEFINE VARIABLE ltrl AS INTEGER NO-UNDO EXTENT 27.
FOR EACH Customer NO-LOCK:
ix = ASC(SUBSTRING(Customer.Name,1,1)).
IF ix < ASC("A") or ix > ASC("Z") THEN ix = EXTENT(ltrl).
ELSE ix = ix - ASC("A") + 1.
ltrl[ix] = ltrl[ix] + 1.
END.
DO jx = 1 TO EXTENT(ltrl) WITH NO-LABELS USE-TEXT:
IF jx <= 26 THEN
DISPLAY CHR(ASC("A") + jx - 1)@ ltr-name AS CHARACTER FORMAT "x(5)".
ELSE
DISPLAY "Other" @ ltr-name.
DISPLAY ltrl[jx].
END.
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Notes
- The
ASC function returns the corresponding value in the specified character
set. By default, the value of SESSION:CHARSET is iso8859-1. You
can set a different internal code page by specifying the Internal
Code Page (-cpinternal) parameter. For more information, see OpenEdge
Development: Internationalizing Applications.
- The ASC function is both double-byte and Unicode enabled. If
the expression argument yields a double-byte
character or multi-byte Unicode character in the target code page,
this function can return a value greater than 255.
