Re: Need to Create an Array of Differences

Here is another take on the lookup hash, which I use now and then.
Much the same as Aristotle's bit. Although, I thought that I would
throw it in anyway, since I had it ready before reading the replies.

    ## use hash search to find everyone in @a but not in @b.
    my %temphash = map { $_ => 1 } @b;
    my @c = grep { !$temphash{ $_ } } @a;
[download]

-xtype

Comment on Re: Need to Create an Array of Differences Download Code

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Re^2: Need to Create an Array of Differences by Anonymous Monk on Dec 16, 2004 at 15:46 UTC
ther's a better way to use grep... my @difference = grep /^@a1/, @a2; #example of sub... my $difference = diff(\@a1,\@a2); sub diff { my @diff = grep /[^@{$_[0]}]/, @{$_1}; return \@diff; } Marco (nemux) Bye.	[reply]
Re^3: Need to Create an Array of Differences by Anonymous Monk on Dec 16, 2004 at 15:54 UTC
sorry ... is impossible to see in my previous message the -> [] then with square brackets visible is : sub diff_2 { my @diff = grep /[[^@{$_[0]]}]/, @{$_[1]}; return \@diff; } Marco	[reply]
Re^4: Need to Create an Array of Differences by xtype (Deacon) on Feb 08, 2005 at 16:49 UTC
Better? If that worked, it wouldn't be semantically the same as Aristotle's, Zaxo's, or my reply. Nor of the perlfaq or tachyon's (which show a difference of both arrays). Did you test your code? It is a nice thought, however, I cannot make that work on 5.6.1, 5.8.1, or 5.8.5 For a simple array of int's @diff is always undef. For an array containing scalars I get "Invalid range in regex" error, which is what I expect. -xtype	[reply]


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