Xbasic

FIELD.IS_VALID Function

Syntax

L Is_Valid()

Description

Is the current field valid.

Discussion

The .IS_VALID() method returns .T. (TRUE) if the pointer to the field is valid; otherwise, it returns .F. (FALSE). The method always returns .F. (FALSE) once the table is closed. Note : The only way to retrieve an invalid field is to use TABLE.FIELD_GET(Field_Number).

Example

dim tbl as P
dim fld as P
tbl = table.open("customer")
 
fld = tbl.field_get(1)
? fld.is_valid()
= .T.
 
fld = tbl.field_get(27)
? fld.is_valid()
= .F.
 
tbl.close()
 
? fld.is_valid(1)
= .F.