如何查找数组的值是否是Perl中哈希的键？

Question

I have an array say @array. I would like to know which values of the array form the keys of a hash, say %hash. Is there is a simple way to do it other than using a for loop?

eg,

 @array = qw (a b c);   
 %hash = ( a => 1, b=> 2 );    

In this case it should just output 'a' and 'b'.

Answer 1

This should do it:

my @array = qw(a b c) ;
my %hash = ( a => 1 , b => 2 ) ;

my @result = grep { exists $hash{$_} } @array ;