Question

I have a list of possible values:

@a = qw(foo bar baz); 

How do I check in a concise way that a value $val is present or absent in @a?

An obvious implementation is to loop over the list, but I am sure TMTOWTDI.

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Thanks to all who answered! The three answers I would like to highlight are:

1. The accepted answer – the most ‘built-in’ and backward-compatible way.

2. RET’s answer is the cleanest, but only good for Perl 5.10 and later.

3. draegtun’s answer is (possibly) a bit faster, but requires using an additional module. I do not like adding dependencies if I can avoid them, and in this case do not need the performance difference, but if you have a 1,000,000-element list you might want to give this answer a try.

Answer 1

Perl’s bulit in grep() function is designed to do this.

@matches = grep( /^MyItem$/, @someArray );  

or you can insert any expression into the matcher

@matches = grep( $_ == $val, @a );