How do I create a switch or case statement?

This is explained in more depth in the the perlsyn manpage. Briefly, there's no official case statement, because of the variety of tests possible in Perl (numeric comparison, string comparison, glob comparison, regex matching, overloaded comparisons, ...). Larry couldn't decide how best to do this, so he left it out, even though it's been on the wish list since perl1.

Here's a simple example of a switch based on pattern matching. We'll do a multi-way conditional based on the type of reference stored in $whatchamacallit: 

    SWITCH:
      for (ref $whatchamacallit) {


	/^$/		&& die "not a reference";


	/SCALAR/	&& do {
				print_scalar($$ref);
				last SWITCH;
			};


	/ARRAY/		&& do {
				print_array(@$ref);
				last SWITCH;
			};


	/HASH/		&& do {
				print_hash(%$ref);
				last SWITCH;
			};


	/CODE/		&& do {
				warn "can't print function ref";
				last SWITCH;
			};


	# DEFAULT


	warn "User defined type skipped";


    }