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
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));
其他回答
As it was asked, here's a recursive object comparison function. And a bit more. Assuming that primary use of such function is object inspection, I have something to say. Complete deep comparison is a bad idea when some differences are irrelevant. For example, blind deep comparison in TDD assertions makes tests unnecessary brittle. For that reason, I'd like to introduce a much more valuable partial diff. It is a recursive analogue of a previous contribution to this thread. It ignores keys not present in a
var bdiff = (a, b) =>
_.reduce(a, (res, val, key) =>
res.concat((_.isPlainObject(val) || _.isArray(val)) && b
? bdiff(val, b[key]).map(x => key + '.' + x)
: (!b || val != b[key] ? [key] : [])),
[]);
BDiff允许检查期望值,同时容忍其他属性,这正是您想要的自动检查。这允许构建各种高级断言。例如:
var diff = bdiff(expected, actual);
// all expected properties match
console.assert(diff.length == 0, "Objects differ", diff, expected, actual);
// controlled inequality
console.assert(diff.length < 3, "Too many differences", diff, expected, actual);
回到完整的解决方案。使用bdiff构建一个完整的传统diff是很简单的:
function diff(a, b) {
var u = bdiff(a, b), v = bdiff(b, a);
return u.filter(x=>!v.includes(x)).map(x=>' < ' + x)
.concat(u.filter(x=>v.includes(x)).map(x=>' | ' + x))
.concat(v.filter(x=>!u.includes(x)).map(x=>' > ' + x));
};
在两个复杂对象上运行上述函数将输出类似于下面的内容:
[
" < components.0.components.1.components.1.isNew",
" < components.0.cryptoKey",
" | components.0.components.2.components.2.components.2.FFT.min",
" | components.0.components.2.components.2.components.2.FFT.max",
" > components.0.components.1.components.1.merkleTree",
" > components.0.components.2.components.2.components.2.merkleTree",
" > components.0.components.3.FFTResult"
]
最后,为了了解值之间的差异,我们可能需要直接eval() diff输出。为此,我们需要一个更丑的bdiff版本,输出语法正确的路径:
// provides syntactically correct output
var bdiff = (a, b) =>
_.reduce(a, (res, val, key) =>
res.concat((_.isPlainObject(val) || _.isArray(val)) && b
? bdiff(val, b[key]).map(x =>
key + (key.trim ? '':']') + (x.search(/^\d/)? '.':'[') + x)
: (!b || val != b[key] ? [key + (key.trim ? '':']')] : [])),
[]);
// now we can eval output of the diff fuction that we left unchanged
diff(a, b).filter(x=>x[1] == '|').map(x=>[x].concat([a, b].map(y=>((z) =>eval('z.' + x.substr(3))).call(this, y)))));
这将输出类似于下面的内容:
[" | components[0].components[2].components[2].components[2].FFT.min", 0, 3]
[" | components[0].components[2].components[2].components[2].FFT.max", 100, 50]
“一族”许可
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。
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 }); }, {});
下面是一个使用Lodash的简单解决方案:
_.differenceWith(a, b, _.isEqual);
注意,两个输入都需要是数组(可能是一个对象的数组)。