OpenEdge Development:<br />Progress 4GL Reference ASC function

Converts a character expression representing a single character into the corresponding ASCII (or internal code page) integer value.

Syntax


ASC ( `expression` [ , `target-codepage` [ , `source-codepage` ] ] )

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").

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 DLC/convmap.cp file (a binary file that contains all of the tables that Progress 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.

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 DLC/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.

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 ltrl AS INTEGER EXTENT 27. DEFINE VARABLE i AS INTEGER. DEFINE VARIABLE j AS INTEGER.FOR EACH customer: i = ASC(SUBSTRING(name,1,1)). IF i < ASC("A") or i > ASC("Z") THEN i = 27. ELSE i = i - ASC("A") + 1. ltrl[i] = ltrl[i] + 1. END.DO j = 1 TO 27 WITH NO-LABELS USE-TEXT: IF j <= 26 THEN DISPLAY CHR(ASC("A") + j - 1) @ ltr-name AS CHARACTER FORMAT "x(5)". ELSE DISPLAY "Other" @ ltr-name. DISPLAY ltrl[j]. END.

r-asc.p

DEFINE VARIABLE ltrl AS INTEGER EXTENT 27.
DEFINE VARABLE i AS INTEGER.
DEFINE VARIABLE j AS INTEGER.FOR EACH customer:
  i = ASC(SUBSTRING(name,1,1)).
  IF i < ASC("A") or i > ASC("Z") THEN i = 27.
  ELSE i = i - ASC("A") + 1.
  ltrl[i] = ltrl[i] + 1.
END.DO j = 1 TO 27 WITH NO-LABELS USE-TEXT:
  IF j <= 26
  THEN DISPLAY CHR(ASC("A") + j - 1) @ ltr-name 
    AS CHARACTER FORMAT "x(5)".
  ELSE DISPLAY "Other" @ ltr-name.
  DISPLAY ltrl[j].
END.

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 double-byte enabled. If the expression argument yields a double-byte character, this function returns a value greater than 255 and less than 65535.

ASC function

Syntax

Notes

See also