Question

In perl, what’s the best way of testing a variable against multiple values?

Something like this (in pseudo code):

if x is in {'q','w','e','r','t'}
  # do something

Answer 1

How about:

if (grep /^x$/, ('q', 'w','e','r','t')) {
  # Do something
}

This works if the values you are comparing are scalars (strings or numbers).

For strings, there is a nice shorthand:

if (grep /^x$/, qw(q w e r t y)) {
  # Do something
}

If you don’t like the regex notation (/^x$/), there is:

grep {$_ eq ‘x’} qw(q w e r t y)

Where you can use $_ to test for anything, not just equality.

If what you want to do is simple (can be expressed in a line), just this will do:

do_something if grep /^x$/, qw(q w e r t y)