如何计算 Ruby 数组中的重复元素

发布于02月20日

我有一个排序数组:

[
  'FATAL <error title="Request timed out.">',
  'FATAL <error title="Request timed out.">',
  'FATAL <error title="There is insufficient system memory to run this query.">'
]

我想得到这样的东西，但它不一定是散列:

[
  {:error => 'FATAL <error title="Request timed out.">', :count => 2},
  {:error => 'FATAL <error title="There is insufficient system memory to run this query.">', :count => 1}
]

推荐答案

下面的代码是你要求的prints.我将让您决定如何实际使用生成您要查找的哈希:

# sample array
a=["aa","bb","cc","bb","bb","cc"]

# make the hash default to 0 so that += will work correctly
b = Hash.new(0)

# iterate over the array, counting duplicate entries
a.each do |v|
  b[v] += 1
end

b.each do |k, v|
  puts "#{k} appears #{v} times"
end

我刚注意到你说数组已经排序了.以上代码不需要排序.使用该属性可能会生成更快的代码.