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

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;
}

其他回答

已经有很多答案发布,但对于那些好奇的人来说,避免编写任何代码来计算具有任何类型结构的两个对象之间的差异,实际上有一个库可以做到这一点。Lodash isEqual只返回true或false,它不返回任何关于更改属性的信息。https://www.npmjs.com/package/deep-diff

它返回两个对象之间差异的完整细节

import DeepDiff from 'deep-diff';
let a = {...} //some object
let b = {...} //some object 
var differences = DeepDiff.diff(a, b);

在这篇文章中也有人提出了类似的问题 获取2个JSON对象之间的差异

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" ]

基于Adam Boduch的回答,我写了这个函数,它在最深层的意义上比较两个对象,返回具有不同值的路径以及从一个或另一个对象中缺失的路径。

代码的编写并没有考虑到效率,在这方面的改进是非常受欢迎的,但这里是基本形式:

var compare = function (a, b) {

  var result = {
    different: [],
    missing_from_first: [],
    missing_from_second: []
  };

  _.reduce(a, function (result, value, key) {
    if (b.hasOwnProperty(key)) {
      if (_.isEqual(value, b[key])) {
        return result;
      } else {
        if (typeof (a[key]) != typeof ({}) || typeof (b[key]) != typeof ({})) {
          //dead end.
          result.different.push(key);
          return result;
        } else {
          var deeper = compare(a[key], b[key]);
          result.different = result.different.concat(_.map(deeper.different, (sub_path) => {
            return key + "." + sub_path;
          }));

          result.missing_from_second = result.missing_from_second.concat(_.map(deeper.missing_from_second, (sub_path) => {
            return key + "." + sub_path;
          }));

          result.missing_from_first = result.missing_from_first.concat(_.map(deeper.missing_from_first, (sub_path) => {
            return key + "." + sub_path;
          }));
          return result;
        }
      }
    } else {
      result.missing_from_second.push(key);
      return result;
    }
  }, result);

  _.reduce(b, function (result, value, key) {
    if (a.hasOwnProperty(key)) {
      return result;
    } else {
      result.missing_from_first.push(key);
      return result;
    }
  }, result);

  return result;
}

您可以使用以下代码段(建议以全页模式运行)尝试代码:

var compare = function (a, b) { var result = { different: [], missing_from_first: [], missing_from_second: [] }; _.reduce(a, function (result, value, key) { if (b.hasOwnProperty(key)) { if (_.isEqual(value, b[key])) { return result; } else { if (typeof (a[key]) != typeof ({}) || typeof (b[key]) != typeof ({})) { //dead end. result.different.push(key); return result; } else { var deeper = compare(a[key], b[key]); result.different = result.different.concat(_.map(deeper.different, (sub_path) => { return key + "." + sub_path; })); result.missing_from_second = result.missing_from_second.concat(_.map(deeper.missing_from_second, (sub_path) => { return key + "." + sub_path; })); result.missing_from_first = result.missing_from_first.concat(_.map(deeper.missing_from_first, (sub_path) => { return key + "." + sub_path; })); return result; } } } else { result.missing_from_second.push(key); return result; } }, result); _.reduce(b, function (result, value, key) { if (a.hasOwnProperty(key)) { return result; } else { result.missing_from_first.push(key); return result; } }, result); return result; } var a_editor = new JSONEditor($('#a')[0], { name: 'a', mode: 'code' }); var b_editor = new JSONEditor($('#b')[0], { name: 'b', mode: 'code' }); var a = { same: 1, different: 2, missing_from_b: 3, missing_nested_from_b: { x: 1, y: 2 }, nested: { same: 1, different: 2, missing_from_b: 3 } } var b = { same: 1, different: 99, missing_from_a: 3, missing_nested_from_a: { x: 1, y: 2 }, nested: { same: 1, different: 99, missing_from_a: 3 } } a_editor.set(a); b_editor.set(b); var result_editor = new JSONEditor($('#result')[0], { name: 'result', mode: 'view' }); var do_compare = function() { var a = a_editor.get(); var b = b_editor.get(); result_editor.set(compare(a, b)); } #objects {} #objects section { margin-bottom: 10px; } #objects section h1 { background: #444; color: white; font-family: monospace; display: inline-block; margin: 0; padding: 5px; } .jsoneditor-outer, .ace_editor { min-height: 230px !important; } button:hover { background: orangered; } button { cursor: pointer; background: red; color: white; text-align: left; font-weight: bold; border: 5px solid crimson; outline: 0; padding: 10px; margin: 10px 0px; } <link href="https://cdnjs.cloudflare.com/ajax/libs/jsoneditor/5.5.10/jsoneditor.min.css" rel="stylesheet" /> <script src="https://cdnjs.cloudflare.com/ajax/libs/jsoneditor/5.5.10/jsoneditor.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script> <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div id="objects"> <section> <h1>a (first object)</h1> <div id="a"></div> </section> <section> <h1>b (second object)</h1> <div id="b"></div> </section> <button onClick="do_compare()">compare</button> <section> <h1>result</h1> <div id="result"></div> </section> </div>

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;
}

这段代码返回一个具有不同值的所有属性的对象,以及两个对象的值。对记录差异很有用。

var allkeys = _.union(_.keys(obj1), _.keys(obj2));
var difference = _.reduce(allkeys, function (result, key) {
  if ( !_.isEqual(obj1[key], obj2[key]) ) {
    result[key] = {obj1: obj1[key], obj2: obj2[key]}
  }
  return result;
}, {});