ISBLANK() returns True or False, depending on whether a string, date or printable numeric value consists entirely of blanks.
ISBLANK() can only assess blank dates for physically defined date fields (excluding packed dates). Physically defined date fields are deemed blank if they solely contain blanks.
ISBLANK() can only assess blank numeric values for physically defined numeric fields that are printable (Numeric of Print data types) - compressed numeric fields (like Binary or Packed field types) cannot be assessed for blanks. Physically defined (printable) numeric fields are deemed blank if they solely contain blanks.
Use ISBLANK() to find records with missing information. This function searches for blank entries in fields that should not contain them and is intended for logical testing.
The field or variable name should be entered as a quoted string.
ISBLANK(C|D|N)
ISBLANK() returns True if the string value C consists entirely of blanks and False if it does not.
ISBLANK() returns True if the date value D consists entirely of blanks and False if it does not.
ISBLANK() returns True if the printable numeric value N consists entirely of blanks and False if it does not.
ISBLANK() only identifies true blanks in printable data, not invalid characters that appear as blanks in the View.
ISBLANK() may not return useful results with character fields that contain null characters (binary zeros). Analyzer and some programming languages use the null character to indicate the end of a string. Consequently, ISBLANK() will not read any character data that follows a null character, including blanks.
ISBLANK(" A") = F
ISBLANK(" ") = T
ISBLANK("") = T