what does my ($subdir, @keywords) = split; do.

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

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Re: what does my ($subdir, @keywords) = split; do. by ikegami (Patriarch) on Mar 17, 2006 at 22:13 UTC
`my ($subdir, @keywords) = split;` [download] is the same as `my @array = split; my ($subdir, @keywords) = @array;` [download] is the same as `my @array = split; my $subdir = $array[0]; my @keywords = @array[1..$#array];` [download] In other words, `$subdir` gets whatever's in front of the first space, and `@keywords` gets all the other fields returned by `split` (if any).	[reply] [d/l] [select]
Re: what does my ($subdir, @keywords) = split; do. by friedo (Prior) on Mar 17, 2006 at 22:13 UTC
You're right on the money. In this case, the list taking the results from `split` consists of `$subdir` and the array `@keywords`. So `$subdir` gets the first item, and `@keywords` gets all the rest. This is a common idiom in Perl, where you often see things like `my ($first, $second, @rest) = @foo;`.	[reply] [d/l] [select]
Re: what does my ($subdir, @keywords) = split; do. by Anonymous Monk on Mar 18, 2006 at 00:58 UTC
I understand that split creates an array from a string No, split creates a list. What is the difference between a list and an array? So @array = split(/\s+/, $_) splits the $_ varible at whitespaces and places the results in array. @array =split does the same. No, split with no arguments does something similar but not quite the same as split( /\s+/, $_ ). You will only notice the difference if the string in $_ has leading whitespace. my ($subdir, @keywords) = split; assigns the list returned from split to the list in the parentheses. If any of the variables in the parentheses is an array or a hash it will receive the remaining items in the list and any variables following said array or hash will not receive anything. This is all explained in the documentation. perldoc perldata	[reply]
Re^2: what does my ($subdir, @keywords) = split; do. by richill (Monk) on Mar 20, 2006 at 22:59 UTC
So as I now understand it ($subdir, @keywords) = split Creates a list from a string in $_. It assigns the first value of that list into $subdir and the remaining values into the @keywords array. ($subdir, @keywords, $empty) = split $empty does not recieve anything because all thevalues go into the @keywords array Thanks	[reply]
Re: what does my ($subdir, @keywords) = split; do. by GrandFather (Saint) on Mar 17, 2006 at 22:14 UTC
`my () = rhs;` puts rhs in a list context. The assignment is made to the elements in the order they are listed. So in the sample you gave the first element in the list ($subdir) gets the first element in the list created by split, and @keywords gets all the rest. DWIM is Perl's answer to Gödel	[reply] [d/l]
Re: what does my ($subdir, @keywords) = split; do. by stu42j (Sexton) on Mar 17, 2006 at 22:13 UTC
$subdir will get the first part.	[reply]