Re: counter issues

You could use the foreach LIST form of the loop here for simplification. It will usually avoid mistakes such as the one you made, categorized as "off by one errors". Also, note that using the matches in list context here may save you from writing (and maintaining) a lot of banal code.

for my $i (0 .. $#array - 1) {
    ($x1, $y1) = ($array[$i] =~ m/\D(\D?\d+\D?\d*)\D(\D?\d+\D?\d*)\D/;
    ($x2, $y2) = ($array[$i + 1] =~ m/\D(\D?\d+\D?\d*)\D(\D?\d+\D?\d*)
+\s*\D/);
}
[download]

Makeshifts last the longest.

Comment on Re: counter issues Download Code

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Re: Re: counter issues by shemp (Deacon) on May 13, 2003 at 15:48 UTC
One caveat with using foreach: What foreach actually does is first create an anonymous copy of the array you are foreach'ing over, then iterates over the copy of the list. So, if your list is rather large, foreach may result in memory usage issues.	[reply]
Re^3: counter issues by Aristotle (Chancellor) on May 13, 2003 at 16:00 UTC
And `for(;;)` internally compiles to a `while(){} continue{}` construct which is pretty slow. If you have determined that the foreach loop is causing problems, you could resort to a regular while loop: `my $i = 0; while($i++ < $#array) { ($x1, $y1) = ($array[$i] =~ m/\D(\D?\d+\D?\d)\D(\D?\d+\D?\d)\D/; ($x2, $y2) = ($array[$i + 1] =~ m/\D(\D?\d+\D?\d)\D(\D?\d+\D?\d) +\s\D/); }` [download] But the foreach loop is much easier to read, so unless it was absolutely necessary I'd stick with that one. Makeshifts last the longest.*	[reply] [d/l]