有没有人知道(如果可能的话，也可以使用 lodash)通过对象键对对象数组进行分组，然后根据分组创建新的对象数组的方法吗?例如，我有一个汽车对象数组:
Does anyone know of a (lodash if possible too) way to group an array of objects by an object key then create a new array of objects based on the grouping? For example, I have an array of car objects:
var cars = [ { 'make': 'audi', 'model': 'r8', 'year': '2012' }, { 'make': 'audi', 'model': 'rs5', 'year': '2013' }, { 'make': 'ford', 'model': 'mustang', 'year': '2012' }, { 'make': 'ford', 'model': 'fusion', 'year': '2015' }, { 'make': 'kia', 'model': 'optima', 'year': '2012' }, ];我想创建一个由 make 分组的新汽车对象数组:
I want to make a new array of car objects that's grouped by make:
var cars = { 'audi': [ { 'model': 'r8', 'year': '2012' }, { 'model': 'rs5', 'year': '2013' }, ], 'ford': [ { 'model': 'mustang', 'year': '2012' }, { 'model': 'fusion', 'year': '2015' } ], 'kia': [ { 'model': 'optima', 'year': '2012' } ] } 推荐答案Timo 的回答 是我会怎么做.简单的_.groupBy，并允许在分组结构中的对象中有一些重复.
Timo's answer is how I would do it. Simple _.groupBy, and allow some duplications in the objects in the grouped structure.
然而，OP 还要求删除重复的 make 键.如果你想一路走下去:
However the OP also asked for the duplicate make keys to be removed. If you wanted to go all the way:
var grouped = _.mapValues(_.groupBy(cars, 'make'), clist => clist.map(car => _.omit(car, 'make'))); console.log(grouped);产量:
{ audi: [ { model: 'r8', year: '2012' }, { model: 'rs5', year: '2013' } ], ford: [ { model: 'mustang', year: '2012' }, { model: 'fusion', year: '2015' } ], kia: [ { model: 'optima', year: '2012' } ] }如果您想使用 Underscore.js 执行此操作，请注意它的 _.mapValues 版本称为 _.mapObject.
If you wanted to do this using Underscore.js, note that its version of _.mapValues is called _.mapObject.