Question

filters = {
  "start_year" => "2009",
  "end_year" => "2011",
  "theme" => "",
  "discipline" => ""
}

filters.length是4，但我想获得2（不仅拥有密钥，还拥有价值的人）

Answer 1

使用count：

filters = {"start_year"=>"2009", "end_year"=>"2011", "theme"=>"", "discipline"=>""}

filters.count { |k, v| v.present? }
#=> 2

Answer 2

您可以使用

filters.reject { |k, v| v.empty? }.length # => 2

Answer 3

解析json字符串。

require 'json'

json_string = <<EOS
{
  "filters": {
    "start_year": "2009",
    "end_year": "2011",
    "theme": "",
    "discipline": ""
  }
}
EOS

h = JSON.parse(json_string)

使用Enumerable#select过滤值：

h['filters'].values.select { |x| x != "" }
# => ["2009", "2011"]
h['filters'].values.select { |x| x != "" }.size
# => 2

Answer 4

filters.values.reject(&:empty?).length

如果您将空值保存为nil而不是''，则可以使用：

filters.values.compact.length

获取没有空值的哈希长度

4 个答案: