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
作为对亚当·博杜赫的回答的补充,这个问题考虑到了性质的差异
const differenceOfKeys = (...objects) =>
_.difference(...objects.map(obj => Object.keys(obj)));
const differenceObj = (a, b) =>
_.reduce(a, (result, value, key) => (
_.isEqual(value, b[key]) ? result : [...result, key]
), differenceOfKeys(b, a));
其他回答
这是基于@JLavoie,使用lodash
let differences = function (newObj, oldObj) {
return _.reduce(newObj, function (result, value, key) {
if (!_.isEqual(value, oldObj[key])) {
if (_.isArray(value)) {
result[key] = []
_.forEach(value, function (innerObjFrom1, index) {
if (_.isNil(oldObj[key][index])) {
result[key].push(innerObjFrom1)
} else {
let changes = differences(innerObjFrom1, oldObj[key][index])
if (!_.isEmpty(changes)) {
result[key].push(changes)
}
}
})
} else if (_.isObject(value)) {
result[key] = differences(value, oldObj[key])
} else {
result[key] = value
}
}
return result
}, {})
}
https://jsfiddle.net/EmilianoBarboza/0g0sn3b9/8/
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 },
}));
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;
}, {});
作为对亚当·博杜赫的回答的补充,这个问题考虑到了性质的差异
const differenceOfKeys = (...objects) =>
_.difference(...objects.map(obj => Object.keys(obj)));
const differenceObj = (a, b) =>
_.reduce(a, (result, value, key) => (
_.isEqual(value, b[key]) ? result : [...result, key]
), differenceOfKeys(b, a));
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)。