Integrate change #14062 from macperl;

[p5sagit/p5-mst-13.2.git] / pod / perlfaq4.pod

diff --git a/pod/perlfaq4.pod b/pod/perlfaq4.pod
index faccc22..08c7651 100644 (file)
--- a/pod/perlfaq4.pod
+++ b/pod/perlfaq4.pod
@@ -1,6 +1,6 @@
 =head1 NAME
 
-perlfaq4 - Data Manipulation ($Revision: 1.7 $, $Date: 2001/10/26 19:46:03 $)
+perlfaq4 - Data Manipulation ($Revision: 1.10 $, $Date: 2002/01/01 22:26:45 $)
 
 =head1 DESCRIPTION
 
@@ -142,7 +142,7 @@ Using perl's built in conversion of 0x notation:
 
     $int = 0xDEADBEEF;
     $dec = sprintf("%d", $int);
- 
+
 Using the hex function:
 
     $int = hex("DEADBEEF");
@@ -322,7 +322,7 @@ will not create a list of 500,000 integers.
 
 =head2 How can I output Roman numerals?
 
-Get the http://www.perl.com/CPAN/modules/by-module/Roman module.
+Get the http://www.cpan.org/modules/by-module/Roman module.
 
 =head2 Why aren't my random numbers random?
 
@@ -334,7 +334,7 @@ than more.
 
 Computers are good at being predictable and bad at being random
 (despite appearances caused by bugs in your programs :-).
-http://www.perl.com/CPAN/doc/FMTEYEWTK/random , courtesy of Tom
+http://www.cpan.org/doc/FMTEYEWTK/random , courtesy of Tom
 Phoenix, talks more about this.  John von Neumann said, ``Anyone who
 attempts to generate random numbers by deterministic means is, of
 course, living in a state of sin.''
@@ -1473,7 +1473,7 @@ If you need to sort on several fields, the following paradigm is useful.
 This can be conveniently combined with precalculation of keys as given
 above.
 
-See http://www.perl.com/CPAN/doc/FMTEYEWTK/sort.html for more about
+See http://www.cpan.org/doc/FMTEYEWTK/sort.html for more about
 this approach.
 
 See also the question below on sorting hashes.
@@ -1635,13 +1635,13 @@ worry you, you can always reverse the hash into a hash of arrays instead:
 =head2 How can I know how many entries are in a hash?
 
 If you mean how many keys, then all you have to do is
-take the scalar sense of the keys() function:
+use the keys() function in a scalar context:
 
-    $num_keys = scalar keys %hash;
+    $num_keys = keys %hash;
 
-The keys() function also resets the iterator, which in void context is
-faster for tied hashes than would be iterating through the whole 
-hash, one key-value pair at a time.
+The keys() function also resets the iterator, which means that you may 
+see strange results if you use this between uses of other hash operators 
+such as each().
 
 =head2 How do I sort a hash (optionally by value instead of key)?
 
@@ -1849,7 +1849,7 @@ in L<perltoot>.
 
 =head2 How can I use a reference as a hash key?
 
-You can't do this directly, but you could use the standard Tie::Refhash
+You can't do this directly, but you could use the standard Tie::RefHash
 module distributed with Perl.
 
 =head1 Data: Misc
@@ -1919,10 +1919,10 @@ respectively.
 =head2 How do I keep persistent data across program calls?
 
 For some specific applications, you can use one of the DBM modules.
-See L<AnyDBM_File>.  More generically, you should consult the FreezeThaw,
-Storable, or Class::Eroot modules from CPAN.  Starting from Perl 5.8
-Storable is part of the standard distribution.  Here's one example using
-Storable's C<store> and C<retrieve> functions:
+See L<AnyDBM_File>.  More generically, you should consult the FreezeThaw
+or Storable modules from CPAN.  Starting from Perl 5.8 Storable is part
+of the standard distribution.  Here's one example using Storable's C<store>
+and C<retrieve> functions:
 
     use Storable; 
     store(\%hash, "filename");