sub myname;
$me = myname $0 or die "can't get myname";
-Note that it functions as a list operator, not as a unary operator; so
+Note that my() functions as a list operator, not as a unary operator; so
be careful to use C<or> instead of C<||> in this case. However, if
you were to declare the subroutine as C<sub myname ($)>, then
C<myname> would function as a unary operator, so either C<or> or
iterator: For each value in EXPR, it aliases C<$_> to the value and
executes the statement. The C<while> and C<until> modifiers have the
usual "C<while> loop" semantics (conditional evaluated first), except
-when applied to a C<do>-BLOCK (or to the now-deprecated C<do>-SUBROUTINE
+when applied to a C<do>-BLOCK (or to the deprecated C<do>-SUBROUTINE
statement), in which case the block executes once before the
conditional is evaluated. This is so that you can write loops like:
LABEL while (EXPR) BLOCK continue BLOCK
LABEL for (EXPR; EXPR; EXPR) BLOCK
LABEL foreach VAR (LIST) BLOCK
+ LABEL foreach VAR (LIST) BLOCK continue BLOCK
LABEL BLOCK continue BLOCK
Note that, unlike C and Pascal, these are defined in terms of BLOCKs,
the sense of the test is reversed.
The C<while> statement executes the block as long as the expression is
-true (does not evaluate to the null string (C<"">) or C<0> or C<"0")>. The LABEL is
-optional, and if present, consists of an identifier followed by a colon.
-The LABEL identifies the loop for the loop control statements C<next>,
-C<last>, and C<redo>. If the LABEL is omitted, the loop control statement
+true (does not evaluate to the null string C<""> or C<0> or C<"0">).
+The LABEL is optional, and if present, consists of an identifier followed
+by a colon. The LABEL identifies the loop for the loop control
+statements C<next>, C<last>, and C<redo>.
+If the LABEL is omitted, the loop control statement
refers to the innermost enclosing loop. This may include dynamically
looking back your call-stack at run time to find the LABEL. Such
desperate behavior triggers a warning if you use the B<-w> flag.
implicitly local to the loop and regains its former value upon exiting
the loop. If the variable was previously declared with C<my>, it uses
that variable instead of the global one, but it's still localized to
-the loop. (Note that a lexically scoped variable can cause problems
-if you have subroutine or format declarations within the loop which
-refer to it.)
+the loop.
The C<foreach> keyword is actually a synonym for the C<for> keyword, so
you can use C<foreach> for readability or C<for> for brevity. (Or because
That kind of switch statement only works when you know the C<&&> clauses
will be true. If you don't, the previous C<?:> example should be used.
-You might also consider writing a hash instead of synthesizing a C<switch>
-statement.
+You might also consider writing a hash of subroutine references
+instead of synthesizing a C<switch> statement.
=head2 Goto
-Although not for the faint of heart, Perl does support a C<goto> statement.
-A loop's LABEL is not actually a valid target for a C<goto>;
-it's just the name of the loop. There are three forms: C<goto>-LABEL,
-C<goto>-EXPR, and C<goto>-&NAME.
+Although not for the faint of heart, Perl does support a C<goto>
+statement. There are three forms: C<goto>-LABEL, C<goto>-EXPR, and
+C<goto>-&NAME. A loop's LABEL is not actually a valid target for
+a C<goto>; it's just the name of the loop.
The C<goto>-LABEL form finds the statement labeled with LABEL and resumes
execution there. It may not be used to go into any construct that