How to check the string is number or letter in Microsoft Dynamics NAV

Hi everybody, today I would like to share a function that probably valuable for you. Sometime you need to investigate whether it is a number form, absolutely Dynamics NAV does not have a standard function like that. This function needs a parameter (text). It is the string in which you want to investigate whether it is a number form. The result of the function returns “TRUE” or “FALSE” as Boolean.

Example

Declare the following variables:

Text Constant	ENU Value
Text000	100,000.00
Text001	It is a number form.
Text002	It isn’t a number form.

IF IsNumeric(Text000) THEN
  MESSAGE(Text001)
ELSE
  MESSAGE(Text002);

The message window displays:  It is a number form.

Now let’s see the code.

LOCAL PROCEDURE IsNumeric@1(p_gText@1000 : Text) : Boolean;
VAR
  i@1001 : Integer;
BEGIN
  FOR i := 1 TO STRLEN(p_gText) DO
    IF (FORMAT(p_gText[i]) IN  ['0'..'9']) OR (FORMAT(p_gText[i]) IN  ['.']) THEN
      IF STRLEN(DELCHR(p_gText, '=', DELCHR(p_gText,'=', '.'))) <= 1 THEN
        EXIT(TRUE)
      ELSE
        EXIT(FALSE)
    ELSE
      EXIT(FALSE);
END;

Documentation

Parameter

String

Type: Text constant or code

The string in which you want to investigate whether it is a number form.

Return Value

Type: Boolean

The result of function returns “TRUE” or “FALSE” as Boolean.

Remark

The IsNumeric function can detect comma (,) and dot (.) in the string so you not need to delete that characters before sent value to the function.