What's the best way to get first character of the string?

karmas has asked for the wisdom of the Perl Monks concerning the following question:

Replies are listed 'Best First'.
Re: What's the best way to get first character of the string? by busunsl (Vicar) on Nov 08, 2001 at 14:01 UTC
`$letter = substr($string, 0, 1);` It's faster (about four times) and easier to understand.	[reply] [d/l]
Re: What's the best way to get first character of the string? by demerphq (Chancellor) on Nov 08, 2001 at 14:59 UTC
Well, as lestrrat and busunsl said you can use substr to do this. I just wanted to say however that there are subtle differences between the two choices. Consider this: `$_="\n"; my ($letter) = /^(.)/; print "Regex: '$letter'\n"; $letter=substr($_,0,1); print "Substr:'$letter'\n";` [download] The two do not produce the same results. Something to consider when you do convert, but not something to keep you from doing so. Using a regex for this type of task is incredible inefficient in comparison to substr. Yves / DeMerphq -- Have you registered your Name Space?	[reply] [d/l]
Re: What's the best way to get first character of the string? by lestrrat (Deacon) on Nov 08, 2001 at 14:01 UTC
If you really just want to get the first character, I'm sure `substr( $str, 0, 1 )` would be sufficient	[reply] [d/l]
TMTOWTDI is your friend! by dragonchild (Archbishop) on Nov 08, 2001 at 20:05 UTC
`my $first = substr $string, 0, 1;` `my $first = substr reverse($string), -1;` `my ($first) = $string =~ /^(.)/sm;` `my $first = (split //, $string)[-1];` `my $first = (reverse(split //, $string))[0];` `my $first = unpack 'a', $string;` Now, of course, some of these are more equal than others. Some are more cryptic than others. Some are also slightly more destructive than others. Take your pick. grins Interestingly enough, the following does not work ... `my ($first) = reverse($string) =~ /(.)$/sm;` [download] ------ We are the carpenters and bricklayers of the Information Age. Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.	[reply] [d/l] [select]
Re: What's the best way to get first character of the string? by mandog (Curate) on Nov 08, 2001 at 20:40 UTC
substr is probably the way to go. For completeness, unpack should probably be put on the long list of other ways to do it. `my $str="hello world\n"; my $lchar=unpack('A1',$str); print "$lchar \n";` [download] email: mandog	[reply] [d/l]