There are times where you really need an index. However, this may not be as often as you think.

In nearly all cases, you are iterating through an array:

for $i ( 0 .. $#array ) {
    print $array[$i];
}
[download]

But Perl (and a surprising number of other languages, particularly functional ones) provide a way to do it without the index:

for $i (@array) {
    print $i;
}
[download]

I'm told that there are even some langauges that have no way of indexing an array at all.

So when people get into debates about 0-vs-1 array indexes, or if array names should not be pluralized so that $list[1] reads better, I must wonder how often these people are using indexes. I would argue that using a lot of indexes is a result of a coder who doesn't really know the language. If you're not using array indexes, then why do you care if the array is indexed at 0 or 1 in your particular language? Why would you care if your language has indexes at all?

One of the few places where I do use indexes is in debugging--I sometimes want to know that the error occured at a certain spot in the array. Also, I use them when parsing xSV files, since I often want a specific entry in the given row.