Re: Re: Lexicals in if() scope gotcha!

[QM]

So for and foreach are not just aliases for each other, as I've seen elsewhere.

Update: So they are aliases, but there are still 2 entities, and the entity chosen depends on context.

[merlyn]

There's a for-loop, with three expressions (sometimes called "C-style for").

There's a foreach-loop, with single scalar (sometimes implied with $_) and a list of values to be walked (sometimes called a "csh-style foreach").

They're definitely two different kinds of loops. However the text for and foreach may be used to introduce either one. The actual loop-style is determined by what follows.

[Ovid]

They are aliases. If you look, you see that for and foreach have been used differently. This should clarify that.

#!/usr/local/bin/perl5.9.1
print "foreach1...\n";
foreach (Foo->new) {}
print "after foreach\n";                                              
+                                  

print "for...\n";
for (my $object = Foo->new; 1 < 0; ) {}
print "after for\n";                                                  
+                              

print "foreach2...\n";
foreach (my $object = Foo->new; 1 < 0; ) {}
print "after foreach\n";                                              
+                                  
package Foo;
sub new { my $self = bless {},shift; print "CREATED $self\n"; $self }
sub DESTROY { print "DESTROYED $_[0]\n" }

__END__
foreach1...
CREATED Foo=HASH(0x81249dc)
DESTROYED Foo=HASH(0x81249dc)
after foreach
for...
CREATED Foo=HASH(0x8124ac0)
after for
foreach2...
CREATED Foo=HASH(0x81249dc)
after foreach
DESTROYED Foo=HASH(0x81249dc)
DESTROYED Foo=HASH(0x8124ac0)