@array holds one two three four.
Printing DATA a few times:
a       b       c
a       b       c
a       b       c
a       b       c
Use of uninitialized value in join or string at mytest.pl line 20, <DATA> line 12.

Use of uninitialized value in join or string at mytest.pl line 20, <DATA> line 12.

Use of uninitialized value in join or string at mytest.pl line 20, <DATA> line 12.

Use of uninitialized value in join or string at mytest.pl line 20, <DATA> line 12.

Array: