Re: How do I loop through a list two or more elements at a time?

in reply to How do I loop through a list two or more elements at a time?

my %hash = @list;
print "$_ - $hash{$_}\n" for keys %hash;
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Re: Answer: How do I loop through a list two or more elements at a time? by Sidhekin (Priest) on Oct 24, 2001 at 15:34 UTC
`my %hash = @list` will stringify the first of every pair of elements in the array, as well as remove all but the last of every pair, the first elements of which stringify to the same "key". ... plus, it is not easily generalizable to more than two elements at a time ... Okay, I guess I should make a suggestion as well: `for (map{{el1=>$list[2$_], el2=>$list[2$_+1]}} 0 .. $#list/2) { # do things with $_->{el1} and $_->{el2} }` [download] In most cases this will be enough though (but I would not trust it with continue blocks): `for (my $i=0 ; $i < @list ; $i+=2) { my ($el1, $el2) = @list[$i,$i+1]; # do things with $el1 and $el2 }` [download] Neither method aliases the list elements; to do that nicely you need a tie() or two. Or just work with references to or directly upon `$list[$i]` and `$list[$i+1]`. The Sidhekin	[reply] [d/l] [select]

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Re: Answer: How do I loop through a list two or more elements at a time?
by Sidhekin (Priest) on Oct 24, 2001 at 15:34 UTC

my %hash = @list will stringify the first of every pair of elements in the array, as well as remove all but the last of every pair, the first elements of which stringify to the same "key".

... plus, it is not easily generalizable to more than two elements at a time ...

Okay, I guess I should make a suggestion as well:

for (map{{el1=>$list[2*$_], el2=>$list[2*$_+1]}} 0 .. $#list/2) {
    # do things with $_->{el1} and $_->{el2}
}
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In most cases this will be enough though (but I would not trust it with continue blocks):

for (my $i=0 ; $i < @list ; $i+=2) {
    my ($el1, $el2) = @list[$i,$i+1];
    # do things with $el1 and $el2
}
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Neither method aliases the list elements; to do that nicely you need a tie() or two. Or just work with references to or directly upon $list[$i] and $list[$i+1].

The Sidhekin

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