Everywhere else in Java, anything with an index starts at 0. Is there a reason for the change here or is this just bad design?
views:
259answers:
6I think both were modeled on an X/Open interface.
Tom Hawtin - tackline
2009-03-05 19:21:06
A:
More human friendly maybe? Also, Java's regular expression Matcher's group starts with 1 as the first matched group.
Steve Kuo
2009-03-05 19:03:22
This is standard with regular expressions as 0 is used to mean the entire match.
Eclipse
2009-03-05 19:06:59
+10
A:
Historically, databases have used 1-based indexing for bound parameters. This probably reflects the origins of relational databases in set theory and mathematics, which index elements starting with one, and use zero to represent a null or empty set.
In shell scripts and regular expressions, the zero index usually means something "special". For example, in the case of shell scripts, the zeroth "argument" is actually the command that was invoked.
The choice for JDBC was deliberate but, ultimately, probably causes more confusion and difficulty than it solves.
erickson
2009-03-05 19:04:54
In mathematics it's usually easier to go with zero-indexing (in my experience (third class BSc)).
Tom Hawtin - tackline
2009-03-05 19:18:48
I don't think zero-based indexing is a mathematical artifact. Every linear algebra book I have starts numbering rows/columns with 1. FORTRAN defaults from 1, if I recall correctly. I think zero-based indexing is a legacy from C and pointer arithmetic.
duffymo
2009-03-05 20:24:59
Personally, I think 0-based indexing is a throwback from C pointer arithmetic which seems to have stuck... to the misfortune of us all.
Software Monkey
2009-03-06 06:32:44
+2
A:
I understand both JDBC and ODBC are based upon the X/Open Call Level Interface. So, it's pre-Java history, like 0-based month numbers.
Tom Hawtin - tackline
2009-03-05 19:20:26
+1
A:
This was part of a plot by the original language designers to weed out the weak. In the original spec, arrays were numbered from -1, and lists with 1 element returned length =0.
Today, only the java Calendar API remains from this diabolical plot.
Steve B.
2009-03-05 19:23:55