In Perl, how do I create a hash whose keys come from a given array?

Question

Let\'s say I have an array, and I know I\'m going to be doing a lot of \"Does the array contain X?\" checks. The efficient way to do this is to turn that array into a hash, wher

Answer 1

 @hash{@array} = (1) x @array;

It's a hash slice, a list of values from the hash, so it gets the list-y @ in front.

From the docs:

If you're confused about why you use an '@' there on a hash slice instead of a '%', think of it like this. The type of bracket (square or curly) governs whether it's an array or a hash being looked at. On the other hand, the leading symbol ('$' or '@') on the array or hash indicates whether you are getting back a singular value (a scalar) or a plural one (a list).