ruby - How to grep elements in array that match patterns from another array? -

i have 2 arrays:

a = ["x2", "x3/x4", "x5/x6/x7", "x8/x9/x10/x11"] b = ["x9/x10", "x3/x4"] 

now need select entries 'a' array regexp of entries array 'b'.

expected result is:

["x3/x4", "x8/x9/x10/x11"] 

how can in ruby?

i'd do:

a.grep(regexp.union(b)) # => ["x3/x4", "x8/x9/x10/x11"]