我有一个数组：
[
{
assignmentId:17,
email:"[email protected]"
expectation: "Make sure to proofread!",
firstName:"John"
id:23
ignoreForFeedback: true
lastName:"Smith"
level:2
levelFraction:null
score:35
},
{
assignmentId:17
countsPerCategory: Array(4)
email:"[email protected]"
firstName:"John"
frequentErrors: Array(5)
id:23
ignoreForGrading: true
lastName:"Smith"
},
{
assignmentId:17,
email:"[email protected]"
expectation: "cite sources",
firstName:"Cindy"
id:45
ignoreForFeedback: true
lastName:"Lee"
level:2
levelFraction:null
score:32
},
{
assignmentId:17
countsPerCategory: Array(4)
email:"[email protected]"
firstName:"Cindy"
frequentErrors: Array(5)
id:45
ignoreForGrading: true
lastName:"Lee"
}
]
我想将具有相同“id”的对象组合到数组中的同一个对象中。它们的公共键也应该组合在一起（例如：'firstName'、'email'）。有人可以建议最好的方法吗？使用 ES6 或 Lodash
您可以使用lodash#groupByby 对数组中的所有项目进行分组id，然后lodash#map与lodash#assign用 a 包装的迭代对象一起使用，lodash#spread以使数组回调作为 的参数列表lodash#assgin。
var result = _(array)
.groupBy('id')
.map(_.spread(_.assign))
.value();
var array = [
{
assignmentId:17,
email:"[email protected]",
expectation: "Make sure to proofread!",
firstName:"John",
id:23,
ignoreForFeedback: true,
lastName:"Smith",
level:2,
levelFraction:null,
score:35
},
{
assignmentId:17,
countsPerCategory: Array(4),
email:"[email protected]",
firstName:"John",
frequentErrors: Array(5),
id:23,
ignoreForGrading: true,
lastName:"Smith"
},
{
assignmentId:17,
email:"[email protected]",
expectation: "cite sources",
firstName:"Cindy",
id:45,
ignoreForFeedback: true,
lastName:"Lee",
level:2,
levelFraction:null,
score:32
},
{
assignmentId:17,
countsPerCategory: Array(4),
email:"[email protected]",
firstName:"Cindy",
frequentErrors: Array(5),
id:45,
ignoreForGrading: true,
lastName:"Lee"
}
];
var result = _(array)
.groupBy('id')
.map(_.spread(_.assign))
.value();
console.log(result);body > div { min-height: 100%; top: 0; }<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.js"></script>这是一个替代解决方案，Array#filter它利用了 的第二个参数，该参数为Array#filter过滤器的回调函数提供了上下文。我们使用this上下文作为一种机制来存储缓存的对象id，然后使用它来决定是否从数组中保留这些对象。
var result = array.filter(function(v) {
return this[v.id]?
!Object.assign(this[v.id], v):
(this[v.id] = v);
}, {});
var array = [
{
assignmentId:17,
email:"[email protected]",
expectation: "Make sure to proofread!",
firstName:"John",
id:23,
ignoreForFeedback: true,
lastName:"Smith",
level:2,
levelFraction:null,
score:35
},
{
assignmentId:17,
countsPerCategory: Array(4),
email:"[email protected]",
firstName:"John",
frequentErrors: Array(5),
id:23,
ignoreForGrading: true,
lastName:"Smith"
},
{
assignmentId:17,
email:"[email protected]",
expectation: "cite sources",
firstName:"Cindy",
id:45,
ignoreForFeedback: true,
lastName:"Lee",
level:2,
levelFraction:null,
score:32
},
{
assignmentId:17,
countsPerCategory: Array(4),
email:"[email protected]",
firstName:"Cindy",
frequentErrors: Array(5),
id:45,
ignoreForGrading: true,
lastName:"Lee"
}
];
var result = array.filter(function(v) {
// does this `id` exist?
return this[v.id]?
// assign existing object with the same id
// from the `this` cache object. Make sure
// to negate the resulting object with a `!`
// to remove this value from the array
!Object.assign(this[v.id], v):
// Assign the value from the `this` cache.
// This also retains this value from the existing
// array
(this[v.id] = v);
}, {});
console.log(result);body > div { min-height: 100%; top: 0; }本文收集自互联网，转载请注明来源。
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