isCOBOL Evolve : Language Reference : ELK Directives : NULLABLE Directive
NULLABLE Directive
The NULLABLE directive mars the field as nullable. Whenever the value of the field is empty, the field will be filled with the word 'null' before being returned in a JSON stream.
>>ELK NULLABLE
or
$ELK NULLABLE
or
*(( ELK NULLABLE ))
or
*>(( ELK NULLABLE ))
Example
In the resulting Web Service, the field p3 will be set to 'null' whenever the p3 data item is spaces:.
       Linkage Section.
      >>ELK INPUT
       01 p1 pic x(10).
       01 p2 pic x(10).
      >>ELK OUTPUT NULLABLE
       01 p3 pic x(10).