如何检查我的哈希是否有来自字符串数组的键？

With Ruby, if I have a hash, what is the fastest way to check if it has a key from an array of strings? So I could do this

使用Ruby，如果我有一个哈希，检查它是否有来自字符串数组的键的最快方法是什么？所以我能做到这一点

has_key = false
arr_of_strings.each do |str|
    if my_hash.has_key?(str)
        has_key = true
        break
    end
end

But taht seems like way too many lines of code for such a simple inquiry.

但对于如此简单的查询，似乎有太多代码行。

3 个解决方案

#1

strings = ['a', 'b', 'c']
hash = {:a => 'apple', :b => 'bob', :d => 'thing'}

has_key = hash.keys.map(&:to_s) & strings  # ['a', 'b']
has_key.any? # true

a one-liner that's similar, hash.keys.detect { |key| strings.include?(key.to_s) }.nil?

一个类似的单行，hash.keys.detect {| key | strings.include？（key.to_s）} .nil？

#2

As simple as this:

就这么简单：

arr_of_strings.any? {|s| my_hash.key?(s) }

Or, to get bonus points for clever-yet-less-readable code:

或者，为巧妙但不易读的代码获得奖励积分：

arr_of_strings.any?(&my_hash.method(:key?)) # => true

#3

To see if the array and the keys have any in common, you can use set intersection:

要查看数组和键是否有任何共同点，可以使用set intersection：

(arr & hash.keys).any?

#1

strings = ['a', 'b', 'c']
hash = {:a => 'apple', :b => 'bob', :d => 'thing'}

has_key = hash.keys.map(&:to_s) & strings  # ['a', 'b']
has_key.any? # true