在javascript中查找一个对象是否是另一个对象的子集

Question

我需要一个函数 isSubset，它在给定两个对象时比较其值并判断一个对象是否是另一个对象的子集。

object1 = { pickUpLocation : {city : 'Hyderabad', state: 'Telangana' }};
object2 = { dist : 322, pickUpLocation:  {city : 'Hyderabad', state: 'Telangana' }};

isSubset(object1, object2); //should return true

object3 = { pickUpLocation : {city : 'Chennai', state: 'Telangana' }}
object4 = { dist : 322, pickUpLocation: {city : 'Hyderabad', state: 'Telangana' }}

isSubset(object3, object4) //should return false as city's value is different

Answer 1

使用 Lodash isMatch

_.isMatch({prop: 'object', id: 3}, {prop: 'object'})

在对象和源之间执行部分深度比较以确定对象是否包含等效的属性值。

Answer 2

这有点晚了，但它可能会帮助某人在不使用任何外部库的情况下寻找答案。

isSubset = (superObj, subObj) => {
    return Object.keys(subObj).every(ele => {
        if (typeof subObj[ele] == 'object') {
            return isSubset(superObj[ele], subObj[ele]);
        }
        return subObj[ele] === superObj[ele]
    });
};

let object1 = { pickUpLocation : {city : 'Hyderabad', state: 'Telangana' }};
let object2 = { dist : 322, pickUpLocation:  {city : 'Hyderabad', state: 'Telangana' }};
console.log(isSubset(object2, object1));

let object3 = { pickUpLocation : {city : 'Chennai', state: 'Telangana' }}
let object4 = { dist : 322, pickUpLocation: {city : 'Hyderabad', state: 'Telangana' }}
console.log(isSubset(object4, object3));

Answer 3

你可以尝试使用isSubset包。

这是真的

isSubset(
  { dist : 322, pickUpLocation:  {city : 'Hyderabad', state: 'Telangana' }},
  { pickUpLocation : {city : 'Hyderabad', state: 'Telangana' }}
);

这是假的

isSubset(
  { dist : 322, pickUpLocation:  {city : 'Hyderabad', state: 'Telangana' }},
  { pickUpLocation : {city : 'Chennai', state: 'Telangana' }}
);

Answer 4

使用 lodash 可以很容易地完成。

import _ from 'lodash'

const isSubset = (aSubset, aSuperset) => (
    _.every(aSubset, (val, key) => _.isEqual(val, aSuperset[key]))
)

用法：

const object1 = { pickUpLocation: { city: 'Hyderabad', state: 'Telangana' }}
const object2 = { dist: 322, pickUpLocation:  { city: 'Hyderabad', state: 'Telangana' }}

isSubset(object1, object2)

Answer 5

上述使用 lodash 的答案有局限性，并未涵盖所有边缘情况。我刚刚想出了适合所有场景的解决方案

import _ from 'lodash';

isSubset(obj1, obj2) {
  let matched = true;
  _.forEach(obj1, (value, key) => {
    if(!requirements || !_.isEqual(value, obj2[key])) {
      matched = false;
      return;
    }
  });
  return matched;
}

案例一：

const obj1 = { foo: 'bar' };
const obj2 = { foo: 'bar', baz: 'qux' };
console.log(isSubset(obj1, obj2)); // true

案例 2：

const obj1 = { foo: 'bar' };
const obj2 = { foo: 'bar' };
console.log(isSubset(obj1, obj2)); // true

案例 3：

const obj1 = { foo: 'bar', baz: 'qux' };
const obj2 = { foo: 'bar'};
console.log(isSubset(obj1, obj2)); // false

案例 4：

const obj1 = undefiend;
const obj2 = undefiend;
console.log(isSubset(obj1, obj2)); // true

案例 5：

const obj1 = undefiend;
const obj2 = { foo: 'bar'};
console.log(isSubset(obj1, obj2)); // true

案例 6：

const obj1 = { foo: 'bar'};
const obj2 = undefiend;
console.log(isSubset(obj1, obj2)); // false

Answer 6

function isSubset(obj1, obj2) {
  for (var key in obj2){
     if (JSON.stringify(obj2[key]) === JSON.stringify(obj1[key]))
        return true;
  }
  return false;
}

编辑：现在是通用的，但如果想要更通用，您应该查看以下链接进行比较 https://stackoverflow.com/a/1144249/5965782

Answer 7

Nima 的第一个答案不可能是正确的，因为要使子集条件为真，“较小”集合中的 所有（不仅仅是 一些）元素需要包含在“更大”的集合。其余基本正确，只需将some 替换为every，并交换两个对象（big 和small）：

/**
 * Determine whether "small" is a subset of "big"
 * @see https://stackoverflow.com/questions/35737312/find-if-an-object-is-subset-of-another-object-in-javascript/48971177#48971177
 */
function isSubset(big, small) {
  const { every, isEqual } = _;
  return every(small, 
    (v, k) => isEqual(v, big[k])
  );
}

// test it!
var object1 = { pickUpLocation : {city : 'Hyderabad', state: 'Telangana' }};
var object2 = { dist : 322, pickUpLocation:  {city : 'Hyderabad', state: 'Telangana' }};
var a = {i:1, j:2, k:3}; var b = {i:1, j:2}; var c = {i:2, j:2};

console.log([
  isSubset(a, b),
  isSubset(a, c),
  isSubset(b, a),
  isSubset(object1, object2),
  isSubset(object2, object1)
]);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.js"></script>

PS：这是另一种方法，但它可能会更慢，因为它会复制内容并且不会提前停止：

function isSubset(big, small) { 
  const { pick, isEqual } = _;
  return isEqual(pick(big, Object.keys(small)), small);
}

Answer 8

这是一个简单的解决方案：

  import _ from "lodash"
  // is a subset of b?
  function isSubset(a, b, merge = false) {
    const assign = merge ? _.merge : _.assign;
    var c = assign(_.cloneDeep(b), a);
    return _.isEqual(b, c);
  }

Answer 9

也有点晚了，但这是另一个不需要任何外部库的解决方案。我以@Akshay Kapoor 的回答为基础，但这一个处理日期和其他定义 valueOf() 的对象的相等性：

const isSubset = (superObj, subObj) =>
    superObj === subObj ||
    typeof superObj === "object" &&
    typeof subObj === "object" && (
        subObj.valueOf() === superObj.valueOf() /* dates & ? */ ||
        Object.keys(subObj).every(k => isSubset(superObj[k], subObj[k]))
    );

Answer 10

function isSubset(obj1, obj2) {
  const matches = [];
  for(const n1 in obj1) {
    let match = false;
    for(const n2 in obj2) {
      if(n1 == n2 && obj1[n1] == obj2[n2]) {
        match = true;
        break;
      }
    }
    matches.push(match);
  }
  return matches.every(Boolean);
}

Answer 11

英文：

object2 中是否有一些键满足其值与object1 之间存在深度相等等条件？

写出来：

_.some(                       // Is there some key
  object2,                    // in object2
  function(val, key) {             // which satisfies the condition that
    return _.isEqual(         // there is deep equality between
      val,                    // its value and
      object1[key]                 // object1?
    );
  }
);

简而言之：

_.some(object2, function(val, key) { return _.isEqual(val, object1[key]); })

在 ES6 中：

_.some(object2, (val, key) => _.isEqual(val, object1[key]))

我的建议是通读 lodash docs 并学习所有 API，或者至少学习主要的 API。例如，如果您不了解_.some 和_.isEqual 等重要例程，则此问题将很难自行解决。另一方面，如果您确实了解它们，那就很简单了。