(1) split has no default second argument, so the $_ needs to be explicit.

Erm . . .

       split /PATTERN/,EXPR,LIMIT

       split /PATTERN/,EXPR

       split /PATTERN/

       split   Splits a string into a list of strings and returns
                [ . . . ]
                                                                      
+          
                If EXPR is omitted, splits the $_ string.
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