$_ $& $+ $` and the other $ 2

[KeziaKristina]

I am new comer in Perl, and i still confuse with the differences among $_ $& $+ and the other $. Anybody can help to explain that. Please with example so I can more understand.
Thanks.

 

[svar]

_ refers to what is currently in memory, e.g. the currenmt iteration variable if this is not name, e.g when reading a file or looping over an array you can say things like
while(<IN>){....
#Here $_ play the role of
#each line in the file that is being looped is $_
# this means you do not really have fo say
my @array=<IN>; foreach my $line(@array){...}
#$_ takes the role of line

next, when you do pattern matching
eg.
my $string='abcAAAabcBBBabcCCC';
die unless $string=~/abc(.*)abc(.*)abc(.)/;
#now $1 is 'AAA', $2='BBB', $3='CCC;

next, if you have an array @a
$#a is the subscript of the last element of the array
(=number of elemnentss of the array -1), since array styarts at 0

$& returns the entire matched string
$+ returns the last bracket matched

There are also many more
$...
I suggest you get the camel book(programming perl) , which is
a must for any beginner and an extremely readable text. Make sure you do NOYT skip the first chapter

svar

 

[Coderifous]

perldoc perlvar

on the command line to view what you could otherwise read in the camel book on this subject.

--jim

 

[KeziaKristina]

Thanks svar..
Your help so helpfull...

Kezia Kristina