如何将键值对附加到 Ruby 中的现有散列？

Question

我是 Ruby 的新手，正在尝试 'inject' key/value 与 Ruby 中的现有哈希配对。我知道您可以使用 << 对数组执行此操作，例如

arr1 = []
a << "hello"

但是我可以为散列做类似的事情吗？所以像

hash1 = {}
hash1 << {"a" => 1, "b" => 2}

基本上，我正在尝试根据条件在循环中推送键值对。

# Encoder: This shifts each letter forward by 4 letters and stores it  in a hash called cipher. On reaching the end, it loops back to the first letter
def encoder (shift_by)
alphabet = []
cipher = {}
alphabet =  ("a".."z").to_a
alphabet.each_index do |x|
        if (x+shift_by) <= 25
            cipher = {alphabet[x] => alphabet[x+shift_by]}
        else
            cipher = {alphabet[x] => alphabet[x-(26-shift_by)]} #Need this piece to push additional key value pairs to the already existing cipher hash.
        end
end

很抱歉将我的整个方法粘贴到这里。谁能帮我解决这个问题？

Answer 1

您可以 merge! 将两个哈希放在一起：

hash1 = {}
hash1.merge!({"a" => 1, "b" => 2})

Answer 2

有3种方式：

.merge(other_hash) Returns a new hash containing the contents of other_hash and the contents of hsh.

hash = { a: 1 }
puts hash.merge({ b: 2, c: 3 }) # => {:a=>1, :b=>2, :c=>3}

.merge!(other_hash) Adds the contents of other_hash to hsh.

hash = { a: 1 }
puts hash.merge!({ b: 2, c: 3 }) # => {:a=>1, :b=>2, :c=>3}

最有效的方法是修改现有哈希值，直接设置新值：

hash = { a: 1 }
hash[:b] = 2
hash[:c] = 3
puts hash # => {:a=>1, :b=>2, :c=>3}

这些方法的相应基准：

       user     system      total        real
   0.010000   0.000000   0.010000 (  0.013348)
   0.010000   0.000000   0.010000 (  0.003285)
   0.000000   0.000000   0.000000 (  0.000918)

如何将键值对附加到 Ruby 中的现有散列？

How do I append a key value pair to an existing hash in Ruby?

ruby

hash

append