Issue when returning null as output

Question

Hi All, 
 I used the following expression in my expression rule 
 a!forEach( items: {1,2,3}, expression: { if( count( wherecontains( fv!item, {5,6,7} ) ) > 6, fv!item, null ) } ) 
 
 When i called this rule in a in process model its returning ; this character , where its not returning null 
 could u please tell me whats the wrong here ? how to return null

Vinay Kumar Rai · Accepted Answer

Hi, 
 
The expression returning list of null, this is expected because you are using loop. 
 
Use reject null. 
 
reject(fn!isnull,foreach(<expression>)) 
 
Thanks

Mike Schmitt · Answer

Also, instead of using reject(), you might be able to return an empty set {} instead of null() for the return of the forEach loop. This shoud cause the resulting array to not contain any entries at all (instead of nulls) for the test condition.

Amit Mishra · Answer

Hi Bhargavi, 
 
This is because you are using null (in else part) and your expression returns set of nulls. Use {} empty set as suggested by Mike in the place of null. You will get 0 item or {}. Thanks