javascript - "pickBy"对象的值数组中的值

Question

我有一个看起来像这样的对象:

let documents = {"A": [{"document":"test1", "serial":"123"}, {"document":"test2", "serial":"456N"}], "B": [{"document":"test3", "serial":"789N"}, {"document":"test24, "serial":"012"}]};

我试图获取序列号以“N”结尾的过滤对象:

{"A": [{"document":"test2", "serial":"456N"}, "B": [{"document":"test3", "serial":"789N"}]}

我在做:

 let result = _.pickBy(documents, (docObjs, client) => {
       return _.filter(docObjs, ({serial}) => {
         return _.endsWith(serial, 'N');
       });
 });

但我得到的是原始对象(与documents相同)。有什么问题吗？

Answer 1

洛达什

使用 _.transform() 迭代客户端的对象。对于每个客户端， filter 使用 _.endsWith() 的文档列表。如果文档列表不是empty(长度为0)，则将具有过滤文档列表的客户端分配给结果对象:

// added client C that will be filtered out
const documents = {"A": [{"document":"test1", "serial":"123"}, {"document":"test2", "serial":"456N"}], "B": [{"document":"test3", "serial":"789N"}, {"document":"test24", "serial":"012"}], "C": [{"document":"test25", "serial":"013"}]};

const result = _.transform(documents, (r, v, k) => {
  const docs = _.filter(v, ({ serial }) => _.endsWith(serial, 'N'));
  if(!_.isEmpty(docs)) r[k] = docs;
});

console.log(result);

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普通 JS

使用 Object.entries() 获取客户端/文档对的数组。使用 Array.map() 和 Array.filter() 删除所有序列号不为 String.endsWith() 字母 N 的文档。使用 Array.filter() 删除所有包含 0 个文档的条目。使用 Array.reduce() 转换回对象:

// added client C that will be filtered out
const documents = {"A": [{"document":"test1", "serial":"123"}, {"document":"test2", "serial":"456N"}], "B": [{"document":"test3", "serial":"789N"}, {"document":"test24", "serial":"012"}], "C": [{"document":"test25", "serial":"013"}]};

const result = Object.entries(documents)
  // filter the least of documents in each client entry
  .map(([k, v]) => [k, v.filter(({ serial }) => serial.endsWith('N'))])
  // filter clients that have 0 documents
  .filter(([k, v]) => v.length)
  // convert back to an object
  .reduce((r, [k, v]) => (r[k] = v, r), {});

console.log(result);

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