Having difficulties with "split"

andybshaker has asked for the wisdom of the Perl Monks concerning the following question:

Hi everyone, I have an array called @Coordinates where each element looks like 1111111..2222222, 3333333..4444444, 5555555..6666666, etc. They are not all the same number, obviously--that is just an example. The point is that in each element, there are 7 or 8 numbers separated by ".." . What I need to do is make an array with elements 1111111, 2222222, 3333333, 4444444, 5555555, 6666666, etc. I tried using a foreach loop with

foreach my $C (@Coordinates){
push (@NewCoordinates, split("..",$C)};
[download]

to no avail. Does anyone have suggestions? Also, I just want to say how helpful this website is. I don't know where I'd be without it.

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Re: Having difficulties with "split" by LanX (Saint) on Apr 26, 2015 at 21:14 UTC
Split takes a regex (not a string) as first argument and `.` is a meta character in regexes. Try escaping with `/\.\./` HTH :) Cheers Rolf _{(addicted to the Perl Programming Language and ☆☆☆☆ :) Je suis Charlie!} update `DB<100> split "..", "1..2..3" => ("", "", "", 3) DB<101> split /\.\./, "1..2..3" => (1, 2, 3)` [download]	[reply] [d/l] [select]
Re: Having difficulties with "split" by AnomalousMonk (Archbishop) on Apr 26, 2015 at 21:15 UTC
`c:\@Work\Perl\monks>perl -wMstrict -MData::Dump -le "my @coords = qw(1111111..2222222 3333333..4444444 5555555..6666666) +; dd \@coords; ;; my @new_coords = map { split m{ \.\. }xms } @coords; dd \@new_coords; " ["1111111..2222222", "3333333..4444444", "5555555..6666666"] [1111111, 2222222, 3333333, 4444444, 5555555, 6666666]` [download] In a regex (which is what split takes as its first argument), the `.` (dot) is a metacharacter meaning "match anything except a newline unless the `/s` modifier is asserted, then match anything", so `.` must be escaped in some way. See perlre, perlretut. Give a man a fish: `<%-(-(-(-<`	[reply] [d/l] [select]
Re: Having difficulties with "split" by Laurent_R (Canon) on Apr 26, 2015 at 21:17 UTC
The dot has a special meaning in regexes. Try this (untested): `foreach my $C (@Coordinates){ push (@NewCoordinates, split /\.\./, $C); };` [download] Je suis Charlie.	[reply] [d/l]
Re: Having difficulties with "split" by MidLifeXis (Monsignor) on Apr 27, 2015 at 14:45 UTC
Instead of escaping the dots explicitly, you could set the RE to escape special characters for you. This is useful when you may need to expand an arbitrary delimiter. `@foo = split("\Q$delim\E", $string);` [download] --MidLifeXis	[reply] [d/l]
Re: Having difficulties with "split" by Anonymous Monk on Apr 26, 2015 at 21:46 UTC
General rule: when you know what you don't want, use split. When you know what you WANT, use regex. `push (@NewCoordinates, $C =~ /\d{7,8}/g);` [download]	[reply] [d/l]
Re^2: Having difficulties with "split" by Anonymous Monk on Apr 26, 2015 at 22:12 UTC
`# then again, even the "map" is not needed @NewCoordinates = "@Coordinates" =~ /\d+/g;` [download]	[reply] [d/l]
Re^2: Having difficulties with "split" by Anonymous Monk on Apr 26, 2015 at 22:06 UTC
`# no need for a "for" loop @NewCoordinates = map /\d+/g, @Coordinates;` [download]	[reply] [d/l]
Re^2: Having difficulties with "split" by Anonymous Monk on Apr 26, 2015 at 21:49 UTC
Oops, I misread as 7 or 8 digit numbers. just use /\d+/g for the regex.	[reply]

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