Rails-显示两个哈希之间的差异

Question

我是新手。如果问题很简单，请原谅。我有两个哈希值hash1和hash2。两者具有相同的键。我需要并排显示两个哈希值，并用不同的颜色突出显示哈希值之间的差异。

Answer 1

Rails具有Hash＃diff：

http://apidock.com/rails/Hash/diff

{1 => 2}.diff(1 => 2)         # => {}
{1 => 2}.diff(1 => 3)         # => {1 => 2}
{}.diff(1 => 2)               # => {1 => 2}
{1 => 2, 3 => 4}.diff(1 => 2) # => {3 => 4}

编辑： 但是，这已在Rails 4.1中删除。为了在更现代的项目中获得相同的结果，可以使用此方法，该方法是从上面得出的。

def hash_diff(first, second)
  first.
    dup.
    delete_if { |k, v| second[k] == v }.
    merge!(second.dup.delete_if { |k, v| first.has_key?(k) })
end

hash_diff({1 => 2}, {1 => 2})         # => {}
hash_diff({1 => 2}, {1 => 3})         # => {1 => 2}
hash_diff({}, {1 => 2})               # => {1 => 2}
hash_diff({1 => 2, 3 => 4}, {1 => 2}) # => {3 => 4}