Xbasic
ISNULL Function
Syntax
Result_Flag as L = isNull(C String )
Arguments
- String
A character string.
Returns
- Result_FlagLogical
Returns .T. (TRUE) if a character string is blank ("") or contains only whitespace characters; otherwise, it returns .F. (FALSE).
Description
Tests if a string is empty or contains only whitespace.
Discussion
ISNULL() can be used to test if a string is empty or contains only whitespace. The function returns true if the string is blank ("") or contains only whitespace characters, such as tabs and spaces.
Example
dim company as c = "Alpha Software" ? isNull(company) = .F. company = "" ? isNull(company) = .T. ' String is a space character ? isNull(" ") = .T. ' String is a tab character ? isNull(" ") = .T. ' String contains only newlines dim str as c = crlf(2) ? isNull(str) = .T. ' String contains a combination of whitespace, including newlines, tabs, and spaces str = crlf(2) + " " + crlf(2) + chr(9) + " " + crlf(2) ? isNull(str) = .T. ? len(str) = 15
See Also