Because the Perl syntax for an array slice is @a[ ... ].

If you enable warnings, you'll see that by using $a[1..3], the 1..3 is treated as a flip-flop operator comparing against $., and under most circumstances will produce false, which in the numeric context gets taken as 0:

c:\test>perl -wE"@a = 0..10; say $a[1..3]; say @a[1..3]"
Use of uninitialized value in range (or flip) at -e line 1.
Argument "" isn't numeric in array element at -e line 1.
0
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In reply to Re^3: Editing just one column in a file by BrowserUk
in thread Editing just one column in a file by ZWcarp

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