Re: Perl For loops

This code doesn't need to be so complicated - for instance why is there an and in there? If the values are always simple integers then the whole $z thing is just testing for equality with 0.

Given that, the loop is just aborting once a 0 values is hit. We also know that the length of the outer array in the result is the count of the first inner array in the matrix. Thus:

my @matrix=([qw(1 2 4 4)],[qw(5 2 0 8)],[qw(9 10 11 12)],);

my @t;
for my $i (0..$#{$matrix[0]}) {
  for my $j (0..$#matrix) {
    last if $matrix[$j][$i] == 0;
    $t[$i][$j] = $matrix[$j][$i];
  }
}
[download]

The result of both your code and mine is the same:

$VAR1 = [
          [ 1, 5, 9 ],
          [ 2, 2, 10 ],
          [ 4 ],
          [ 4, 8, 12 ],
        ]
[download]

Update: I must have missed Util's comment, which is virtually identical to mine :)

Comment on Re: Perl For loops Select or Download Code

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Re^2: Perl For loops by atemon (Chaplain) on Jul 04, 2007 at 07:31 UTC
Hi Monks, I don't know what is the purpose of getting it in a "for" loop. But if we are concerned only about output or $t, can't we do something like `$t = [ @matrix ]` [download] so that the entire program would be `my @matrix=([qw(1 2 4 4)],[qw(5 2 0 8)],[qw(9 10 11 12)],); my $t = [ @matrix ];` [download] Or even simpler like `my $t = [ [qw(1 2 4 4)],[qw(5 2 0 8)],[qw(9 10 11 12)], ];` [download] cheers! -VC Update: Appologies for the carelessness & waste of time.	[reply] [d/l] [select]
Re^3: Perl For loops by aufflick (Deacon) on Jul 06, 2007 at 03:34 UTC
well, because your way $t is: `[ [ 1, 2, 4, 4 ], [ 5, 2, 0, 8 ], [ 9, 10, 11, 12 ], ]` [download] when it should be: `[ [ 1, 5, 9 ], [ 2, 2, 10 ], [ 4 ], [ 4, 8, 12 ], ]` [download] kinda different...	[reply] [d/l] [select]