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…
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
这是我对这个问题的解决办法
const _ = require('lodash');
var objects = [{ 'x': 1, 'y': 2, 'z':3, a:{b:1, c:2, d:{n:0}}, p:[1, 2, 3] }, { 'x': 2, 'y': 1, z:3, a:{b:2, c:2,d:{n:1}}, p:[1,3], m:3 }];
const diffFn=(a,b, path='')=>_.reduce(a, function(result, value, key) {
if(_.isObjectLike(value)){
if(_.isEqual(value, b[key])){
return result;
}else{
return result.concat(diffFn(value, b[key], path?(`${path}.${key}`):key))
}
}else{
return _.isEqual(value, b[key]) ?
result : result.concat(path?(`${path}.${key}`):key);
}
}, []);
const diffKeys1=diffFn(objects[0], objects[1])
const diffKeys2=diffFn(objects[1], objects[0])
const diffKeys=_.union(diffKeys1, diffKeys2)
const res={};
_.forEach(diffKeys, (key)=>_.assign(res, {[key]:{ old: _.get(objects[0], key), new:_.get(objects[1], key)} }))
res
/*
Returns
{
x: { old: 1, new: 2 },
y: { old: 2, new: 1 },
'a.b': { old: 1, new: 2 },
'a.d.n': { old: 0, new: 1 },
'p.1': { old: 2, new: 3 },
'p.2': { old: 3, new: undefined },
m: { old: undefined, new: 3 }
}
*/
其他回答
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]。
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。
我知道这并不能直接回答OP的问题,但我是通过搜索如何删除lodash被引导到这里的。希望这能帮助到和我处境相似的人。
这要归功于@JohanPersson。我在这个答案的基础上实现了对深度嵌套值的比较,并获得对差异的键引用
getObjectDiff = (obj1, obj2) => { const obj1Props = Object.keys(obj1); const obj2Props = Object.keys(obj2); const keysWithDiffValue = obj1Props.reduce((keysWithDiffValueAccumulator, key) => { const propExistsOnObj2 = obj2.hasOwnProperty(key); const hasNestedValue = obj1[key] instanceof Object && obj2[key] instanceof Object; const keyValuePairBetweenBothObjectsIsEqual = obj1[key] === obj2[key]; if (!propExistsOnObj2) { keysWithDiffValueAccumulator.push(key); } else if (hasNestedValue) { const keyIndex = keysWithDiffValueAccumulator.indexOf(key); if (keyIndex >= 0) { keysWithDiffValueAccumulator.splice(keyIndex, 1); } const nestedDiffs = getObjectDiff(obj1[key], obj2[key]); for (let diff of nestedDiffs) { keysWithDiffValueAccumulator.push(`${key}.${diff}`); } } else if (keyValuePairBetweenBothObjectsIsEqual) { const equalValueKeyIndex = keysWithDiffValueAccumulator.indexOf(key); keysWithDiffValueAccumulator.splice(equalValueKeyIndex, 1); } return keysWithDiffValueAccumulator; }, obj2Props); return keysWithDiffValue; } const obj1 = {a0: {a1: {a2: {a3: 'Im here'}}}}; const obj2 = {a0: {a1: {a2: {a3: 'Not here', b3: 'some'}}}}; console.log('final', getObjectDiff(obj1, obj2));
我们需要在两个json更新之间获取delta,以跟踪数据库更新。也许其他人会觉得这很有用。
https://gist.github.com/jp6rt/7fcb6907e159d7851c8d59840b669e3d
const {
isObject,
isEqual,
transform,
has,
merge,
} = require('lodash');
const assert = require('assert');
/**
* Perform a symmetric comparison on JSON object.
* @param {*} baseObj - The base object to be used for comparison against the withObj.
* @param {*} withObj - The withObject parameter is used as the comparison on the base object.
* @param {*} invert - Because this is a symmetric comparison. Some values in the with object
* that doesn't exist on the base will be lost in translation.
* You can execute again the function again with the parameters interchanged.
* However you will lose the reference if the value is from the base or with
* object if you intended to do an assymetric comparison.
* Setting this to true will do make sure the reference is not lost.
* @returns - The returned object will label the result of the comparison with the
* value from base and with object.
*/
const diffSym = (baseObj, withObj, invert = false) => transform(baseObj, (result, value, key) => {
if (isEqual(value, withObj[key])
&& has(withObj, key)) {
return;
}
if (isObject(value)
&& isObject(withObj[key])
&& !Array.isArray(value)) {
result[key] = diffSym(value, withObj[key], invert);
return;
}
if (!invert) {
result[key] = {
base: value,
with: withObj[key],
};
return;
}
if (invert) {
result[key] = {
base: withObj[key],
with: value,
};
}
});
/**
* Perform a assymmetric comparison on JSON object.
* @param {*} baseObj - The base object to be used for comparison against the withObj.
* @param {*} withObj - The withObject parameter is used as the comparison on the base object.
* @returns - The returned object will label the values with
* reference to the base and with object.
*/
const diffJSON = (baseObj, withObj) => {
// Deep clone the objects so we don't update the reference objects.
const baseObjClone = JSON.parse(JSON.stringify(baseObj));
const withObjClone = JSON.parse(JSON.stringify(withObj));
const beforeDelta = diffSym(baseObjClone, withObjClone);
const afterDelta = diffSym(withObjClone, baseObjClone, true);
return merge(afterDelta, beforeDelta);
};
// By Example:
const beforeDataObj = {
a: 1,
c: { d: 2, f: 3 },
g: 4,
h: 5,
};
const afterDataObj = {
a: 2,
b: 3,
c: { d: 1, e: 1 },
h: 5,
};
const delta = diffJSON(beforeDataObj, afterDataObj);
// Assert expected result.
assert(isEqual(delta, {
a: { base: 1, with: 2 },
b: { base: undefined, with: 3 },
c: {
d: { base: 2, with: 1 },
e: { base: undefined, with: 1 },
f: { base: 3, with: undefined },
},
g: { base: 4, with: undefined },
}));
我需要知道它们的某个嵌套属性是否不同
其他答案为这个问题提供了可能令人满意的解决方案,但它非常困难和常见,似乎有一个非常受欢迎的包来帮助解决这个问题。
要使用这个包,你需要npm i deep-object-diff,然后:
const { diff } = require('deep-object-diff');
var a = {};
var b = {};
a.prop1 = 2;
a.prop2 = { prop3: 2 };
b.prop1 = 2;
b.prop2 = { prop3: 3 };
if (!_.isEqual(a, b)) {
const abDiff = diff(a, b);
console.log(abDiff);
/*
{
prop2: {
prop3: 3
}
}
*/
}
// or alternatively
const abDiff = diff(a, b);
if(!_.isEmpty(abDiff)) {
// if a diff exists then they aren't deeply equal
// perform needed actions with diff...
}
下面是一个更详细的案例,直接从他们的文档中删除属性:
const lhs = {
foo: {
bar: {
a: ['a', 'b'],
b: 2,
c: ['x', 'y'],
e: 100 // deleted
}
},
buzz: 'world'
};
const rhs = {
foo: {
bar: {
a: ['a'], // index 1 ('b') deleted
b: 2, // unchanged
c: ['x', 'y', 'z'], // 'z' added
d: 'Hello, world!' // added
}
},
buzz: 'fizz' // updated
};
console.log(diff(lhs, rhs)); // =>
/*
{
foo: {
bar: {
a: {
'1': undefined
},
c: {
'2': 'z'
},
d: 'Hello, world!',
e: undefined
}
},
buzz: 'fizz'
}
*/
有关实现细节和其他使用信息,请参阅该repo。