in reply to Re^2: Array got modified!
in thread Array got modified!

Could you explain, in your own words, what does the while ( my $ele = <@arr> ) { do?

Once you do, go check the docs!

It may seem to do what you seem to want if you are unlucky enough and the @arr doesn't contain anything interesting to the diamond operator, but even then it's horribly inefficient.

Jenda
Enoch was right!
Enjoy the last years of Rome.

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Re^4: Array got modified!
by exilepanda (Friar) on Oct 10, 2011 at 12:51 UTC
    Hmm... my try is to take that array as a file handle to read, like @ARGV;

    I add up this code : 

    @x = qw/Foo Bar Blaz/;
#@x = qw//;

print "Before: @x$/";
while ( my $ele = <@x> ) {
 next unless $ele;
 print "$ele becomes ";
 $ele =~ s/^(.)/x$1/;
 print $ele . $/;
}
print "$/After: @x";
__END__

Then I have :
  Before: Foo Bar Blaz
  Foo becomes xFoo
  Bar becomes xBar
  Blaz becomes xBlaz

  After: Foo Bar Blaz

    [download]
    Is this work out properly by accident? This is what I want though...
    My observation is:
    if that's a empty array, it skips fine.
    And, without the diamond quote, it loops forever...
[reply]
[d/l]
      $ perl -MO=Deparse junk
print "Before: @x$/";
use File::Glob ();
while (defined(my $ele = glob(join $", @x))) {
    do {
        next unless $ele;
        print "$ele becomes ";
        $ele =~ s/^(.)/x$1/;
        print $ele . $/
    };
}
print "$/After: @x";
__DATA__
junk syntax OK

      [download]

      See glob, readline

[reply]
[d/l]
        Sorry but I don't get it.

        First, after a perldoc on the glob, I get totally lost, I never touch a Unix shell, so I couldn't imagine or relate to anything.. I am on Win32 all time..

        Second, would you explain more for what is your code try to demonstrate? Is this a safe/suggested way to do what I want? or it's proving my way is danger? or anything else ?

[reply]
      Yes, it's working by accident (no spaces nor * in @x). For example: 
      perl -E '@arr=("a b",
    "c d",
    qw/e f g h a*/);
while (my $e = <@arr>) {
    say $e
}'

      [download]
      gives this output for me:
      a
b
c
d
e
f
g
h
address.txt
address.txt~
analytic
ascii.htm
aux-no-lex.lst

      [download]
[reply]
[d/l]
[select]
        Got it! Didn't aware of it at all....
        Lesson learned!! Thanks a lot!!! =)
[reply]

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