选择和排序数据 JSON

Question

我需要开发一个简单的应用程序来从 JSON 列表中选择和排序数据，包含两个规则 - “include”和“sort_by”

示例： 输入数据：

{"data": [{"name": "John", "email": "john2@mail.com"},
          {"name": "John", "email": "john1@mail.com"},
          {"name": "Jane", "email": "jane@mail.com"}]}

条件：

{"condition": {"include": [{"name": "John"}], "sort_by": ["email"]}}

输出：

{"result": [{"name": "John", "email": "john1@mail.com"},
            {"name": "John", "email": "john2@mail.com"}]}

Answer 1

您可以使用for..in 循环轻松实现此结果，以获取您需要的属性filter，然后sort（使用自定义排序）相应地得到它。

const obj = {
  data: [
    { name: "John", email: "john2@mail.com" },
    { name: "John", email: "john1@mail.com" },
    { name: "Jane", email: "jane@mail.com" },
  ],
};

const test = {
  condition: {
    include: [{ name: "John" }],
    sort_by: ["email"],
  },
};

let prop;
for (let key in test.condition.include[0]) {
  prop = key;
}

const include_prop = test.condition.include[0][prop];
const sort_by_prop = test.condition.sort_by[0];

const result = obj.data
  .filter((o) => o[prop] === include_prop)
  .sort((a, b) => (b[sort_by_prop] > a[sort_by_prop] ? -1 : 1));

const resultObj = { result };
console.log(resultObj);

Answer 2

这里有两件事要做，排序和过滤...

const data = [
  {"name": "John", "email": "john2@mail.com"},
  {"name": "John", "email": "john1@mail.com"},
  {"name": "Jane", "email": "jane@mail.com"}
]
const sortAndInclude = (data, include, sortBy) => {
  //filter by name
  const newData = data.filter(x => x[include[0]] == include[1])
  
  // sort by sortBy
  newData.sort(function(a, b) {
    var aa = a[sortBy].toUpperCase(); // ignore upper and lowercase
    var bb = b[sortBy].toUpperCase(); // ignore upper and lowercase
  if (aa < bb) {
    return -1;
  }
  if (aa > bb) {
    return 1;
  }

  // names must be equal
  return 0;
});
  
  return newData
  
}

console.log(sortAndInclude(data, ["name", "John"], ['email']))

编辑：过滤器说明...

filter 方法返回一个新数组，我们称之为newData。 filter 方法遍历数组并删除条件为假的任何元素。在这种情况下，我们调用元素x。我们希望函数是可重用的，所以我们使用x[include[0]] 和include[1]。我们的include 变量是更宽函数的第二个参数，所以当我们调用sortAndInclude(data, ["name", "John"], ['email']) 时，include 是一个包含两个元素["name", "John"] 的数组。因此，在过滤方法的条件下，当我们说x[include[0]] == include[1] 时，我们实际上是在说x["name"] == x["John"]。因此过滤器方法将删除元素名称键不具有“John”值的任何元素。

Here's some more info on filters.