add perltrap entry about "${#a}", as suggested by

andy barfoot <abarfoot@eng.auburn.edu>

p4raw-id: //depot/perl@1559

1 files changed, 17 insertions, 0 deletions

diff --git a/pod/perltrap.pod b/pod/perltrap.pod
index 1b954a357d..852d8e9826 100644
--- a/pod/perltrap.pod
+++ b/pod/perltrap.pod
@@ -650,6 +650,23 @@ Better parsing in perl 5
     # perl4 prints: is zero
     # perl5 warns: "Useless use of a constant in void context" if using -w
 
+=item * Parsing
+
+String interpolation of the C<$#array> construct differs when braces
+are to used around the name.
+
+    @ = (1..3);
+    print "${#a}";
+
+    # perl4 prints: 2
+    # perl5 fails with syntax error
+
+    @ = (1..3);
+    print "$#{a}";
+
+    # perl4 prints: {a}
+    # perl5 prints: 2
+
 =back
 
 =head2 Numerical Traps