我有2个不同的嵌套对象,我需要知道它们是否在其中一个嵌套属性中有不同。

var a = {};
var b = {};

a.prop1 = 2;
a.prop2 = { prop3: 2 };

b.prop1 = 2;
b.prop2 = { prop3: 3 };

对象可以更复杂,有更多嵌套的属性。但这是一个很好的例子。我可以选择使用递归函数或lodash的东西…


当前回答

此解决方案返回一个具有修改过的属性的对象。

_.reduce(a, (r, v, k) => { return _.merge(r, _.isEqual(v, b[k]) ? {} : { [k]: v }); }, {});

其他回答

如果你需要知道哪些属性是不同的,使用reduce():

_.reduce(a, function(result, value, key) {
    return _.isEqual(value, b[key]) ?
        result : result.concat(key);
}, []);
// → [ "prop2" ]

在没有使用lodash/下划线的情况下,我已经编写了这段代码,并且可以很好地对object1和object2进行深入比较

function getObjectDiff(a, b) {
    var diffObj = {};
    if (Array.isArray(a)) {
        a.forEach(function(elem, index) {
            if (!Array.isArray(diffObj)) {
                diffObj = [];
            }
            diffObj[index] = getObjectDiff(elem, (b || [])[index]);
        });
    } else if (a != null && typeof a == 'object') {
        Object.keys(a).forEach(function(key) {
            if (Array.isArray(a[key])) {
                var arr = getObjectDiff(a[key], b[key]);
                if (!Array.isArray(arr)) {
                    arr = [];
                }
                arr.forEach(function(elem, index) {
                    if (!Array.isArray(diffObj[key])) {
                        diffObj[key] = [];
                    }
                    diffObj[key][index] = elem;
                });
            } else if (typeof a[key] == 'object') {
                diffObj[key] = getObjectDiff(a[key], b[key]);
            } else if (a[key] != (b || {})[key]) {
                diffObj[key] = a[key];
            } else if (a[key] == (b || {})[key]) {
                delete a[key];
            }
        });
    }
    Object.keys(diffObj).forEach(function(key) {
        if (typeof diffObj[key] == 'object' && JSON.stringify(diffObj[key]) == '{}') {
            delete diffObj[key];
        }
    });
    return diffObj;
}

一个简单而优雅的解决方案是使用_。isEqual,它执行深度比较:

Var a = {}; Var b = {}; A.prop1 = 2; A.prop2 = {prop3: 2}; B.prop1 = 2; B.prop2 = {prop3: 3}; console.log(_。isEqual (a, b));//如果不同则返回false < script src = " https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js " > < /脚本>

然而,这个解决方案并没有显示哪个属性是不同的。

这是一个简单的带有Lodash深度差异检查器的Typescript,它将生成一个新对象,只包含旧对象和新对象之间的差异。

例如,如果我们有:

const oldData = {a: 1, b: 2};
const newData = {a: 1, b: 3};

结果对象将是:

const result: {b: 3};

它还兼容多层深层对象,对于数组,它可能需要一些调整。

import * as _ from "lodash";

export const objectDeepDiff = (data: object | any, oldData: object | any) => {
  const record: any = {};
  Object.keys(data).forEach((key: string) => {
    // Checks that isn't an object and isn't equal
    if (!(typeof data[key] === "object" && _.isEqual(data[key], oldData[key]))) {
      record[key] = data[key];
    }
    // If is an object, and the object isn't equal
    if ((typeof data[key] === "object" && !_.isEqual(data[key], oldData[key]))) {
      record[key] = objectDeepDiff(data[key], oldData[key]);
    }
  });
  return record;
};

对于无意中发现这条线索的人,这里有一个更完整的解决方案。它将比较两个对象,并给出所有属性的键,这些属性要么只存在于object1中,要么只存在于object2中,要么同时存在于object1和object2中,但值不同:

/*
 * Compare two objects by reducing an array of keys in obj1, having the
 * keys in obj2 as the intial value of the result. Key points:
 *
 * - All keys of obj2 are initially in the result.
 *
 * - If the loop finds a key (from obj1, remember) not in obj2, it adds
 *   it to the result.
 *
 * - If the loop finds a key that are both in obj1 and obj2, it compares
 *   the value. If it's the same value, the key is removed from the result.
 */
function getObjectDiff(obj1, obj2) {
    const diff = Object.keys(obj1).reduce((result, key) => {
        if (!obj2.hasOwnProperty(key)) {
            result.push(key);
        } else if (_.isEqual(obj1[key], obj2[key])) {
            const resultKeyIndex = result.indexOf(key);
            result.splice(resultKeyIndex, 1);
        }
        return result;
    }, Object.keys(obj2));

    return diff;
}

下面是一个输出示例:

// Test
let obj1 = {
    a: 1,
    b: 2,
    c: { foo: 1, bar: 2},
    d: { baz: 1, bat: 2 }
}

let obj2 = {
    b: 2, 
    c: { foo: 1, bar: 'monkey'}, 
    d: { baz: 1, bat: 2 }
    e: 1
}
getObjectDiff(obj1, obj2)
// ["c", "e", "a"]

如果你不关心嵌套对象并且想要跳过lodash,你可以替换_。isEqual用于正常的值比较,例如obj1[key] === obj2[key]。