javascript - 使用lodash在javascript中的对象数组中按值计数

Question

我有一个对象数组，如下所示：

var input_array = [{
    role_name: 'Full Stack Developer',
    position_id: 'b0f00e68-5adc-4209-aec2-9c4962550ab1',
    email_address: '[e-mail]',
    application_id: '1dd45634-c283-4a96-a28a-d8a63c418329',
    state: 'qualified',
    closing_date: '2018-10-28 06:30:00' },
{
    role_name: 'Delivery Representative',
    position_id: '090276f0-3fca-4b2a-85ed-697d21c405a0',
    email_address: '[e-mail]',
    application_id: 'aa7fe2dd-b141-4c64-8350-a1d57bfaa502',
    state: 'interview',
    closing_date: '2018-10-28 06:30:00' },
{
    role_name: 'Delivery Representative',
    position_id: '12345678-5adc-4209-aec2-9c4962550ab1',
    email_address: '[e-mail]',
    application_id: '166da0ac-aaf1-400d-9a62-e37962f66653',
    state: 'interview',
    closing_date: '2018-10-28 06:30:00' },
{
    role_name: 'Delivery Representative',
    position_id: '090276f0-3fca-4b2a-85ed-697d21c405a0',
    email_address: '[e-mail]',
    application_id: 'da09a617-8e82-43c0-b1ea-725110a2c4cb',
    state: 'interview',
    closing_date: '2018-10-28 06:30:00' },
{
    role_name: 'Delivery Representative',
    position_id: '12345678-5adc-4209-aec2-9c4962550ab1',
    email_address: '[e-mail]',
    application_id: '1d55a51a-ecd1-43ea-9cf4-fed101dbebda',
    state: 'offer',
    closing_date: '2018-10-28 06:30:00' },
{
    role_name: 'Micro Space Planner',
    position_id: 'fe30930f-7d9f-4953-8939-6d9924462b2b',
    email_address: '[e-mail]',
    application_id: '293bd084-64f0-4c83-9b5d-aa304e44f066',
    state: 'screening',
    closing_date: '2018-10-28 06:30:00' },
{
    role_name: 'Delivery Representative',
    position_id: '12345678-5adc-4209-aec2-9c4962550ab1',
    email_address: '[e-mail]',
    application_id: '2adc5236-989d-49f2-ab3e-cb7e42798b77',
    state: 'qualified',
    closing_date: '2018-10-28 06:30:00' },
{
    role_name: 'Micro Space Planner',
    position_id: 'fe30930f-7d9f-4953-8939-6d9924462b2b',
    email_address: '[e-mail]',
    application_id: '293bd084-64f0-4c83-9b5d-aa304e44f066',
    state: 'screening',
    closing_date: '2018-10-28 06:30:00' },
{
    role_name: 'Delivery Representative',
    position_id: '12345678-5adc-4209-aec2-9c4962550ab1',
    email_address: '[e-mail]',
    application_id: '2adc5236-989d-49f2-ab3e-cb7e42798b77',
    state: 'qualified',
    closing_date: '2018-10-28 06:30:00' }]

我想将具有状态的对象计算为与每个职位相对应的offer和 interview。我正在使用 npmlodash库。

我已经检查了关于 SO 的几个问题，关于 group by 和 count 使用过滤器，但在我的情况下，位置 id 是动态的。所以我不能设置 position_id 的具体值，我可以使用它来对对象进行分组。

例如 position_id as '12345678-5adc-4209-aec2-8b3962550ce7' 包含 1 个 offer 和 1 interview

预期输出：

{
    role_name: 'Delivery Representative',
    position_id: '12345678-5adc-4209-aec2-9c4962550ab1',
    email_address: '[e-mail]',
    offer_count: 1,
    interview_count: 1
},
{
    role_name: 'Micro Space Planner',
    position_id: 'fe30930f-7d9f-4953-8939-6d9924462b2b',
    email_address: '[e-mail]',
    offer_count: 0,
    interview_count:0
},
{
    role_name: 'Delivery Representative',
    position_id: '090276f0-3fca-4b2a-85ed-697d21c405a0',
    email_address: '[e-mail]',
    offer_count: 0,
    interview_count:2
}

标签： javascriptarraysnode.jslodashjavascript-objects

Answer 1

您可以使用 和 的组合reduce，map无论是原生 JS 还是 lodash 版本。首先，通过位置 id 减少记录，然后映射对象条目以生成所需的数组。

Object.entries(input_arr.reduce((acc, item) => {
  if (!acc[item.position_id]) {
    acc[item.position_id] = {
      interview_count: 0,
      offer_count: 0,
      email_address: item.email_address,
      role_name: item.role_name
    };
  }

  if (item.state === 'interview') acc[item.position_id].interview_count += 1;
  if (item.state === 'offer') acc[item.position_id].offer_count += 1;
  return acc;
}, {})).map(([position_id, {email_address, interview_count, offer_count, role_name}]) => {
  return {
    position_id,
    email_address,
    interview_count,
    offer_count,
    role_name
  };
});

这是一个小提琴