reject function used with index function

Question

How can we fetch only not null cases from this index function. pls share the detailed query

Konduru Chaitanya · Answer

Hello om786 
 
 This is not sufficient information. Please share the more details. Here is something near to what you have asked for, but not accurate as I am not clear of what you are trying to do and what you have tried. 
 reject(
 isnull(_),
 index(local!activeTasks,"c26",null)
)

Mike Schmitt · Answer

I prefer to avoid "reject()" and the other primitive looping functions where possible (which is almost everywhere), as a!forEach() does a better job, is more flexible, and is easier to understand. Here we iterate over an array of "local!activeTasks" (pulling out arbitrary property "myProperty" first using the property () rule, which does the same thing as index() but we're using the appropriate one for the job it's doing here). When any given iteration is blank, the loop returns an empty set. (We wrap the whole thing in a!flatten() since otherwise if every iteration returns an empty set, it would give you an array of empty sets, which a!flatten() collapses to the desired single empty set). 
 a!flatten(
 a!forEach(
 property(local!activeTasks, "myProperty", null()),
 if(
 a!isNotNullOrEmpty(fv!item),
 fv!item,
 {}
 )
 )
)