Use a dispatch table.

There is plenty amount of documentation on how using Switch breaks your program in surprising ways on this site.

Hello fionbarr,

When I use 'given/when' I get the message 'given is experimental' and the program will not compile.

Are you using a very old version of Perl? According to perlexperiment, the smartmatch feature was introduced in Perl 5.10.0, so unless your version is older than that, the program should compile OK — but emit warnings — as long as you remember to use feature 'switch':

 0:33 >perl -we "use feature 'switch'; my $c = 42; given ($c) { when (
+$_ < 50) { print 'Yes!' } }"
given is experimental at -e line 1.
when is experimental at -e line 1.
Yes!
 0:33 >
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The warnings can be turned off with this pragma:

no warnings 'experimental::smartmatch';
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But if you’re going to use when, you should still replace the topicaliser given with its more prosaic alternative for, as explained by brian_d_foy in his article “Use for() instead of given().”

However, even the use of when is not recommended for production code. For other switch options, begin with How-do-I-create-a-switch-or-case-statement of perlfaq7. And if a dispatch table doesn’t meet your particular needs, what’s wrong with if/elsif/.../else, anyway? :-)

Hope that helps,

I never saw that usage of 'no warnings'. Thanks to all who answered

use strict;
use warnings;
my $score = 77;
my $grade
    = $score >= 90 ? 'A'
    : $score >= 80 ? 'B'
    : $score >= 70 ? 'C'
    : $score >= 60 ? 'D'
    :                'F'
    ;
print "$grade\n";
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Dunno why the Perl language did not include some form of switch in any of its incarnations, but I also do not care for the various graft-on implementations that try to provide it.   Corion’ suggestion to use a dispatch table ... which is simply an array or hash of subrefs ... is a good one.   Otherwise, frankly, I would just knuckle down and make peace with if...elsif..elsif....   If you are careful to spin-off the various cases into separate subs, for clarity, it actually is about as sweet as the (syntactic ...) sugar.