OB Is empty

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4D v20.6

OB Is empty


OB Is empty ( object ) -> Function result

Parameter	Type	Description
object	Object, Object Field	Structured object
Function result	Boolean	True if object is empty or undefined, otherwise False

Description

The OB Is empty command returns True if object is undefined or empty, and False if object is defined (initialized) and contains at least one property.

object must have been created using the C_OBJECT command or designate a 4D object field.

Example

Here are the different results of this command as well as the OB Is defined command, depending on the context:

 C_OBJECT($ref)

 $empty:=OB Is empty($ref) // True

 $def:=OB Is defined($ref) // False

 

 OB SET($ref;"name";"Susie";"age";4)

  // $ref="{"name":"Susie","age":4}"

 $empty:=OB Is empty($ref) // False

 $def:=OB Is defined($ref) // True

 

 OB REMOVE($ref;"name")

 OB REMOVE($ref;"age")

 $empty:=OB Is empty($ref) // True

 $def:=OB Is defined($ref) // True