why doesn't /^$_$/ behave?

[Sara]

OK, $_ is "1", and my aray contains "13", but not "1".

This matches:

grep /^$_$/, @a;

But this doesn't match:

my $xi = $_;
grep /^$xi$/, @a;

p 5.6.1 on RH.

 

[Jeff 'japhy' Pinyan]

[posted & mailed]

OK, $_ is "1", and my aray contains "13", but not "1".

This matches:

grep /^$_$/, @a;

Because in grep() and map(), $_ is locally set to the value in the list
you're looking at. That's why you write

grep /foo/, @a;

because /foo/ is really $_ =~ /foo/.

$_ = 10;
grep print("_ = $_\n"), 1, 2, 3;