join with @ 打印错误的结果

Question

I would like to know how can I use the sign @ together with join operator; this yields a wrong result:

my $string1  = '00aabb';
my $string2  = '02babe';
print join ("A",@ $string1, $string2);

Namely:

$ perl b.pl
02babe

So how can I use @ within join that would concatenate the two strings and joins them with a separator A ? I come out of the assumption that join requires an array as its second argument, and it thus should begin with @ . The mere

print join("A", $string1, $string2);

works fine, but I want to make it work with @ preceded.

Answer 1

join does not require an array as its second argument; it requires a list (which is different from an array):

join EXPR,LIST

Your 2nd code example works fine because the 2nd and 3rd arguments make up a list of 2 items. Here is a way to use join if you already have an array variable ( @strings ):

use warnings;
use strict;

my $string1  = '00aabb';
my $string2  = '02babe';

print join ("A", $string1, $string2);
print "\n";

my @strings = ($string1, $string2);

print join ("A", @strings);
print "\n";

Prints:

00aabbA02babe
00aabbA02babe

The @ sign is what is used to denote an array variable.

See also perldoc perldata .

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Note that if you had used strict , you would have gotten an error message.