CHR function

Converts an integer value to its corresponding character value.

Syntax


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

expression

An expression that yields an integer value that you want to convert to a character value.

If the value of expression is in the range of 1 to 255, CHR returns a single character. This character might not be printable or might not display on certain terminals. For a value greater than 255 and less than 65535, the CHR function checks for a corresponding lead-byte value. If the integer value corresponds to a valid lead-byte, the CHR returns a double-byte character.

The CHR function returns a null string if the expression yields a value outside of the range 1 to 65534 or the expression yields a value in the range 256 to 65534 and the value does not correspond to a valid lead-byte.

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 DLC/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 CHR function returns a null string. Before returning a character value, the CHR function converts expression from source-codepage to target-codepage. The returned character value is relative to target-codepage. If you do not specify target-codepage, no code page conversions occur.

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 DLC/convmap.cp file. If you supply a non-valid name, the CHR function returns a null string. The source-codepage specifies the name of the code page to which expression is relative. The default value of source-codepage is the value of SESSION:CHARSET.

Example

The r-chr.p procedure initializes the 26 elements of the letter array to the letters A through Z.

r-chr.p
DEFINE VARIABLE ix AS INTEGER NO-UNDO. DEFINE VARIABLE letter AS CHARACTER NO-UNDO FORMAT "X(1)" EXTENT 26. DO ix = 1 TO 26: letter[ix] = CHR((ASC("A")) - 1 + ix). END. DISPLAY SKIP(1) letter WITH 2 COLUMNS NO-LABELS TITLE "T H E A L P H A B E T".

r-chr.p

DEFINE VARIABLE ix     AS INTEGER   NO-UNDO. 
DEFINE VARIABLE letter AS CHARACTER NO-UNDO FORMAT "X(1)" EXTENT 26. 
DO ix = 1 TO 26: 
  letter[ix] = CHR((ASC("A")) - 1 + ix). 
END. 
DISPLAY SKIP(1) letter WITH 2 COLUMNS NO-LABELS 
  TITLE "T H E  A L P H A B E T".

Notes

The CHR function returns the corresponding character in the specified code page. 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 Deployment: Startup Command and Parameter Reference.

The CHR function is double-byte enabled. For a value greater than 255 and less than 65535, it checks for a lead-byte value. If the lead-byte value is valid, the AVM creates and returns a double-byte character.