如何在 Perl 中找到一个数组中而不是另一个数组中的元素?
问题描述：
我有两个数组，我想找到一个数组中的元素而不是另一个:
I have two arrays and I want to find elements that are in one array but not another:
例如:
@array1 = ("abc", "cde", "fgh", "ijk", "lmn")
@array2 = ("abc", "fgh", "lmn")
我需要结束:
@array3 = ("cde", "ijk")
答
将第二个数组的元素放入一个散列中，以便高效检查其中是否包含特定元素，然后过滤第一个数组的元素那些不在第二个数组中的元素:
Put the elements of the second array into a hash, for efficient checking to see whether or not a particular element was in it, then filter the first array for just those elements that were not in the second array:
my %array2_elements;
@array2_elements{ @array2 } = ();
my @array3 = grep ! exists $array2_elements{$_}, @array1;