Re: (jeffa) Re: How to open sub FH when filename is passed to sub?

Thank you for your help jeffa!

I am a beginner for perl. My new hash keys I can read in
from a file, but my values I have to get them from my main
hash.Why you use shift? Does it mean it can change
different filename everytime you call sub? if it is so,
that is what I want.
Please help

Comment on Re: (jeffa) Re: How to open sub FH when filename is passed to sub?

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More than you ever wanted to know about shift @_ by jeffa (Bishop) on May 05, 2002 at 16:56 UTC
You are most welcome. Yes, that is exactly why i use shift. shift returns the first value from an array, in this case it is the implied array @_ which is used by Perl to store the arguments passed to a given subroutine. I could have used this instead: `my $filename = shift @_; # or even my ($filename) = @_; # multiple arguments are best caught this way: my ($first,$second,$third) = @_; # but some folks prefer my $first = shift; my $second = shift; my $third = shift;` [download] Most (if not all...) other languages use an argument list to specify what a subroutine can be 'passed', as well as a return type (together these form the 'signature'). For example, in Java, these: Read more... (5 kB)	[reply] [d/l] [select]

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More than you ever wanted to know about shift @_
by jeffa (Bishop) on May 05, 2002 at 16:56 UTC

shift

  my $filename = shift @_;

  # or even
  my ($filename) = @_;

  # multiple arguments are best caught this way:
  my ($first,$second,$third) = @_;

  # but some folks prefer
  my $first  = shift;
  my $second = shift;
  my $third  = shift;
[download]