javascript - 从数组中删除精确重复的行

Question

我有一个 Javascript 列表。

var list = [{
    ID: "2566",
    NAME: "ENTERPRISE EXPENSE",
    EXECUTE: "LOAD_DIMENTION",
    TYPE: "PROCEDURE"
  },
  {
    ID: "1234",
    NAME: "LOAD EXPENSE FACT",
    EXECUTE: "LOAD_EXPENSE_FACT",
    TYPE: "STORED PROCEDURE"
  },
  {
    ID: "RI0031",
    NAME: "LOAD HEAD COUNT",
    EXECUTE: "LOAD_HEADCOUNT_FACT",
    TYPE: "STORED PROCEDURE"
  },
  {
    NAME: "Not Required",
    EXECUTE: "Not Required",
    TYPE: "Not Required"
  },
  {
    NAME: "Duplicate",
    EXECUTE: "Duplicate",
    TYPE: "Duplicate"
  },
  {
    ID: "RI04",
    NAME: "CALCULATE FAST",
    EXECUTE: "FF_CALC",
    TYPE: "STORED PROCEDURE"
  },
  {
    NAME: "FORMULAS",
    EXECUTE: "FF_CALC",
    TYPE: "STORED PROCEDURE"
  },
  {
    ID: "RI0031",
    NAME: "LOAD HEAD COUNT",
    EXECUTE: "LOAD_HEADCOUNT_FACT",
    TYPE: "STORED PROCEDURE"
  },
  {
    ID: "RI04",
    NAME: "CALCULATE FAST",
    EXECUTE: "FF_CALC",
    TYPE: "STORED PROCEDURE"
  },
  {
    NAME: "FORMULAS",
    EXECUTE: "FF_CALC",
    TYPE: "STORED PROCEDURE"
  },
  {
    ID: "RID005",
    NAME: "CALCULATE FAST GROUP",
    EXECUTE: "FF_CALC",
    TYPE: "STORED PROCEDURE"
  },
  {
    NAME: "Not Required",
    EXECUTE: "Not Required",
    TYPE: "Not Required"
  },
  {
    NAME: "Duplicate",
    EXECUTE: "Duplicate",
    TYPE: "Duplicate"
  }
];

此列表有许多重复行。我想从中删除所有重复的行。

该对象还可以有 10 个以上的属性，因此检查每个属性并不是解决方案。另外，无论我上网的方式要么是一维数组，要么是通过特定属性删除重复项。如何维护包含所有唯一行的列表？

Answer 1

来自the MDN article on JSON.stringify :

Properties of non-array objects are not guaranteed to be stringified in any particular order. Do not rely on ordering of properties within the same object within the stringification.

不应直接比较每个对象的 JSON 字符串化，而应首先使用 Object.entries 获取 [key, value] 对的数组，然后按key 的字符串值。然后，无论 JSON.stringify 实现如何，都可以安全地对这个排序的条目数组进行字符串化和比较。

请注意，我下面的示例使用了最新的 ES6 功能，包括 Set和 Object.entries 。要将此代码转译为 ES5 并运行它，请访问 https://babeljs.io/repl/ .

function deepUnique (array) {
  return [...new Set(array.map(e => JSON.stringify(Object.entries(e).sort(compareEntriesByKey))))].map(e => objectFromEntries(JSON.parse(e)))
}

function compareEntriesByKey (a, b) {
  return a[0] < b[0] ? -1 : a[0] === b[0] ? 0 : 1
}

function objectFromEntries (entries) {
  let result = {}
  entries.forEach(e => result[e[0]] = e[1])
  return result
}

var list = [{
    ID: "2566",
    NAME: "ENTERPRISE EXPENSE",
    EXECUTE: "LOAD_DIMENTION",
    TYPE: "PROCEDURE"
  },
  {
    ID: "1234",
    NAME: "LOAD EXPENSE FACT",
    EXECUTE: "LOAD_EXPENSE_FACT",
    TYPE: "STORED PROCEDURE"
  },
  {
    ID: "RI0031",
    NAME: "LOAD HEAD COUNT",
    EXECUTE: "LOAD_HEADCOUNT_FACT",
    TYPE: "STORED PROCEDURE"
  },
  {
    NAME: "Not Required",
    EXECUTE: "Not Required",
    TYPE: "Not Required"
  },
  {
    NAME: "Duplicate",
    EXECUTE: "Duplicate",
    TYPE: "Duplicate"
  },
  {
    ID: "RI04",
    NAME: "CALCULATE FAST",
    EXECUTE: "FF_CALC",
    TYPE: "STORED PROCEDURE"
  },
  {
    NAME: "FORMULAS",
    EXECUTE: "FF_CALC",
    TYPE: "STORED PROCEDURE"
  },
  {
    ID: "RI0031",
    NAME: "LOAD HEAD COUNT",
    EXECUTE: "LOAD_HEADCOUNT_FACT",
    TYPE: "STORED PROCEDURE"
  },
  {
    ID: "RI04",
    NAME: "CALCULATE FAST",
    EXECUTE: "FF_CALC",
    TYPE: "STORED PROCEDURE"
  },
  {
    NAME: "FORMULAS",
    EXECUTE: "FF_CALC",
    TYPE: "STORED PROCEDURE"
  },
  {
    ID: "RID005",
    NAME: "CALCULATE FAST GROUP",
    EXECUTE: "FF_CALC",
    TYPE: "STORED PROCEDURE"
  },
  {
    NAME: "Not Required",
    EXECUTE: "Not Required",
    TYPE: "Not Required"
  },
  {
    NAME: "Duplicate",
    EXECUTE: "Duplicate",
    TYPE: "Duplicate"
  }
];

console.log(deepUnique(list))

归功于Kind user用于创建an answer using both JSON and Set在我发布我的之前。