Re: How do I remove an element from any array while iterating over it in a loop?

This works fine and deletes any element equal to 5 while iterating over the loop. You are using this so you can infer that the unless($uid) conditional is always executed (meaning you never get a true value in $uid) thus you splice your array down to nothing. Add a print $uid debugging statement an I reckon you will find this is the case.

$" = "~";

@ary = qw( 5 1 2 3 4 5 6 7 8 9 5 );

print "@ary\n";

for my $i ( 0 .. $#ary ) {
    splice @ary, $i, 1 if $ary[$i] == 5;
}

print "@ary\n";

Update - Senator Retracts earlier statement

Hmm as pointed out by the ever vigilant MeowChow this does not work in some cases although it does on the test given. This will work. Proviso you will lose all undefined elements in your array.

@ary = qw( 0 1 5 5 5 0 5 5 5 1 0 );

$" = "~";

print "@ary\n";

for my $i ( 0 .. $#ary ) {
    # undefine bad element
    undef $ary[$i] if $ary[$i] == 5;
}

# now remove undefined elements
@ary = grep{ defined }@ary;

print "@ary\n";
[download]

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print

Comment on Re: How do I remove an element from any array while iterating over it in a loop? Download Code

Replies are listed 'Best First'.
(MeowChow) Re2: How do I remove an element from any array while iterating over it in a loop? by MeowChow (Vicar) on Aug 30, 2001 at 23:05 UTC
`@ary = qw( 1 5 5 5 5 2 );` [download] Would you care to revise your statement, senator? :) MeowChow s aamecha.s a..a\u$&owag.print	[reply] [d/l]
Re: (MeowChow) Re2: How do I remove an element from any array while iterating over it in a loop? by tachyon (Chancellor) on Aug 31, 2001 at 14:10 UTC
This is how the original should have been and -w would have well warned me that it was broke. You need to understand that splice will change the length of an array and so to the index of the next element when in a loop. Public humiliation again as MeowChow walks up, LOL and saunters off :-) `my @ary = qw( 0 1 5 5 5 0 5 5 5 1 0 ); $" = "~"; print "@ary\n"; my $deletions = 0; for my $i ( 0 .. $#ary ) { if ($ary[$i-$deletions] == 5) { splice @ary, ($i-$deletions), 1; $deletions++; } } print "@ary\n";` [download] cheers tachyon s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print	[reply] [d/l]
Re (tilly) 4: How do I remove an element from any array while iterating over it in a loop? by tilly (Archbishop) on Sep 01, 2001 at 04:15 UTC
Another item to be aware of. Removing every other element in a list through using splice is O(n*n). Using grep is O(n). In this case it probably doesn't matter. But with a lot of filtering operations that is a good item to be aware of.	[reply]