Your code suggestion: 
while (<DATA>) {
  my $code = (split)[1];
  for my $x (0..$#all) {
    if($code eq $all[$x]) {
      print $_;
      last;
    }
  }
}

[download]
 I suppose you have written it this way to stay close to the OP's coding style, but it should be mentioned that indexing the @all array is not necessary and not particularly perlish. 
while (<DATA>) {
  my $code = (split)[1];
  for my $x ( @all ) {
    if($code eq $x) {
      print $_;
      last;
    }
  }
}

[download]
Now it becomes apparent that what the loop does is really a grep operation: 
while (<DATA>) {
  my $code = (split)[1];
  print if grep $_ eq $code, @all;
  }
}

[download]
Finally, it turns out that grep can be replaced with a hash lookup when the list @all is replaced by a hash: 
my %all =  map +( $_ => 1), qw(7723 7725 9908 7765 7874);
$all{ (split)[ 1]} and print while <DATA>;

[download]
Anno

Update: Stylistic change, pomposity tuned down a notch.

In reply to Re^2: Help in using arrays by Anno
in thread Help in using arrays by rsriram

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