Subroutine can return both scalar and list context values, so return a list context values as in our case here. One can use wantarray() to tell which context as stated in the perldoc -f wantarray documentation, and I quote "Returns true if the context of the currently executing subroutine or "eval" is looking for a list value. Returns false if the context is looking for a scalar. Returns the undefined value if the context is looking for no value (void context)."

E.g:

 my @values=get_values(); # subroutine called
    print @values;  ## print 12345 not 1,2,3,4,5
     sub get_values{
         my @init_val=grep $_=>1..5;
       if(wantarray){ # test list context
         return @init_val;
       }else{return join",",split}
      }
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