Null coalescing using 4D ?:)
NVL
Defined a default value if NULL
C_VARIANT($value;$Obj;$NullObject)
$Obj:=New object()
$value:=NVL($NullObject;$Obj) // $value eq. $Obj (same as Choose($NullObject=Null;$Obj;$NullObject) )
C_VARIANT($value;$Obj)
$Obj:=New object()
For each ($value;NVL ($Obj.collection;New collection))
// do something
End for each
COALESCE
Same as NVL
but with more than one possible NULL
element.
C_VARIANT($value;$Obj)
$Obj:=New object()
For each ($value;COALESCE ($Obj.collection1;$Obj.collection3;New collection))
// do something
End for each
NVF
Checking if NULL
before applying any formula.
If (NVF ($collection;Formula($1.length>2)))
For each ($element;$collection)
End for each
End if
PATH_COALESCE
Get the first defined value from an object.
$obj:=New object("a"; New object("b";"d");"dot.dot"; 5)
$value:=PATH_COALESCE($obj;New collection("a.z";"d";"a.b";"dot.dot");$defaultValue)
// Will return "d" because "a.b" is the first 'correct' path
GetValueOrDefault
Alternative to Null Coalescing, in case you want to provide the default value for the data type,
you can use Bool
, Int
, String
or for any data type GetValueOrDefault
If(Bool($Obj.success))
// do something d
End if
For each ($value;GetValueOrDefault($Obj.collection1))
// do something
End for each