小编jlo*_*ren的帖子

这会在Perl v5.20中引发错误:

use strict;
use warnings;
my @a = (2,3,9);
my %b = map { "number $_" => 2*$_ } @a;

错误:

syntax error at a.pl line 4, near "} @a"
Execution of a.pl aborted due to compilation errors.

这不是:

use strict;
use warnings;
my @a = (2,3,9);
my %b = map { "number ".$_ => 2*$_ } @a;

为什么$_在mapBLOCK 中不允许插值？