Else: what's the difference?

What's the difference

between cascaded IFs

   if( cond1 ) {
      ...
   } elsif( cond2 ) {
      ...
   } else {
       ...
   }

and a nested IF in the ELSE part:


   if( cond1 ) {
   } else {
        if( cond2 ) {
            ...
        } else {
            ...
        }
   }


?

Not much - except for intent.  The latter calls out the ELSE part, the IF cond2 part, emphasizing its separateness. The latter pivots easily to a nested IF in the THEN part. The cascaded IF probably needs to be transformed to the nested IF on the WELSE part, and then pivoted.

Note that the cascaded IF is often used to express a concurrent IF:


   if    cond1 => ...
   ::    cond2 => ...
   else ...
   fi

where the difference is meaningful: in the concurrent IF all of the condityions, cond1 and cond2, are evaluated.  Indeed, some argue that there should be no ELSE clause for a concurrent IF.

--

I wonder if there could be some useful difference made between cascaded IF and nested IF in the ELSE part.