The homework question just defines @colors and @drop and says to remove the things in drop from colors, that's it.

If perl was math we could say: 


@colors - @drop = @colors
But perl is perl so we have to say: 

@colors = -@drop + @colors
Perl can do that, like this: 

@colors = (miniature @drop program here) @colors
The flow of information goes: 
      __<________________________<__
   #4/                              \#3
@colors = (miniature > program > here) @colors
         #2\__<___________________<___/#1
The mini program goes inside map {} like: 

@colors = map { my $x = join '|', @drop; /$x/ ? () : $_ } @colors;
Unrolled: 

@colors =
  map {
    my $x = join '|', @drop; # make a regex
    /$x/ ? () : $_           # simpler than it looks
  }
@colors;

In reply to Re: The error says the value is uninitialized, but it works anyway by Anonymous Monk
in thread The error says the value is uninitialized, but it works anyway by mizducky

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