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- 4D Language Reference
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- Objects (Language)
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Structure of 4D language objects
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Using object notation
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Shared objects and shared collections
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New object
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New shared object
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OB Class
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OB Copy
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OB Entries
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OB Get
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OB GET ARRAY
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OB GET PROPERTY NAMES
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OB Get type
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OB Instance of
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OB Is defined
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OB Is empty
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OB Is shared
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OB Keys
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OB REMOVE
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OB SET
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OB SET ARRAY
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OB SET NULL
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OB Values
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Storage
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OB Is empty
| OB Is empty ( object ) -> Function result | ||||||||
| Parameter | Type | Description | ||||||
| object | Object, Object Field |
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Structured object | |||||
| Function result | Boolean |
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True if object is empty or undefined, otherwise False | |||||
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 _O_C_OBJECT command or designate a 4D object field.
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
Product: 4D
Theme: Objects (Language)
Number:
1297
Created: 4D v14
Modified: 4D v15
4D Language Reference ( 4D v20 R7)
