合并和分组对​​象数组，不重复

Question

我有一个重复的对象数组列表。他们每个人都有不同的财产。我想将属性唯一地分组到一个特定的数组对象而不重复数组对象。如果可以在lodash库中完成，那就太棒了。

数据

[  
   {  
      "mc":{  
         "id":"mc-id1"
      },
      "meal":{  
         "id":32,
         "mc_id":"mc-id1",
         "name":"BulletProof Vanilla"
      }
   },
   {  
      "mc":{  
         "id":"mc-id1",
      },
      "meal":{  
         "id":31,
         "mc_id":"mc-id1",
         "name":"Olive oil"
      }
   },
   {  
      "mc":{  
         "id":"mc-id2"
      },
      "meal":{  
         "id":38,
         "mc_id":"mc-id2",
         "name":"Organic fish tail"
      }
   },
   {  
      "mc":{  
         "id":"mc-id2"
      },
      "meal":{  
         "id":37,
         "mc_id":"mc-id2",
         "name":"Organic fish head"
      }
   }
]

预期输出

[  
   {  
      "mc":{  
         "id":"mc-id1"
      },
      "meal":[{  
         "id":32,
         "mc_id":"mc-id1",
         "name":"BulletProof Vanilla"
      },{
      "meal":{  
         "id":31,
         "mc_id":"mc-id1",
         "name":"Olive oil"
      }]
   },
   {  
      "mc":{  
         "id":"mc-id2"
      },
      "meal":[{  
         "id":38,
         "mc_id":"mc-id2",
         "name":"Organic fish tail"
      },{  
         "id":37,
         "mc_id":"mc-id2",
         "name":"Organic fish head"
      }]
   }
]

Answer 1

我先使用groupby，然后使用map来获得所需的输出。

var array = [  
	   {  
	      "mc":{  
	         "id":"mc-id1"
	      },
	      "meal":{  
	         "id":32,
	         "mc_id":"mc-id1",
	         "name":"BulletProof Vanilla"
	      }
	   },
	   {  
	      "mc":{  
	         "id":"mc-id1",
	      },
	      "meal":{  
	         "id":31,
	         "mc_id":"mc-id1",
	         "name":"Olive oil"
	      }
	   },
	   {  
	      "mc":{  
	         "id":"mc-id2"
	      },
	      "meal":{  
	         "id":38,
	         "mc_id":"mc-id2",
	         "name":"Organic fish tail"
	      }
	   },
	   {  
	      "mc":{  
	         "id":"mc-id2"
	      },
	      "meal":{  
	         "id":37,
	         "mc_id":"mc-id2",
	         "name":"Organic fish head"
	      }
	   }
	];
    var array = _.groupBy(array, function(o){
	  return o.mc.id;
	})

	array = _.map(array, function(o){
	  return {
	    mc : _.first(o).mc,
	    meal: _.map(o, function(p){
	    return p.meal
	  })
	  }
	})

	console.log(array)

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

Answer 2

作为一个可怕的一个班轮（假设你的输入是一个叫做数据的变量）：

_.map(_.groupBy(data, (o) => o.mc.id), (i, k) => {return {mc: k, meal: _.map(i, (m) => m.meal)}})

稍微详细一点的方法：

var groupedByMc = _.groupBy(data, (obj) => obj.mc.id)
var output = _map(groupedByMc, (obj, key) => {
    return { 
        mc: key, 
        meal: _.map(obj, m) => m.meal 
    }
})

Answer 3

1. 您可以使用lodash#groupBy按mc.id对数组中的每个项目进行分组。

2. 将lodash#mapValues与部分创建的lodash#map函数一起使用lodash#partial，将每个mc.id与meals相关联。

3. 使用lodash#toPairs将mc.id密钥和meal对象转换为键值对数组。例如{a:1, b:2}将为[['a', '1'],['b', '2']]。

4. 使用lodash#map使用部分创建的lodash#zipObjectDeep函数，使用lodash#partial将键值对数组分配到各自的键中：mc.id和{{1 }}

meal

＆＃13;
＆＃13;
var result = _(array)
  // group each item by mc.id key
  .groupBy('mc.id') 
  // associate each mc.id by all of the grouped meals
  .mapValues(_.partial(_.map, _, 'meal')) 
  // convert key-value into an array pair values
  .toPairs()
  // associate the array values into their respective keys
  .map(_.partial(_.zipObjectDeep, ['mc.id', 'meal']))
  // get the value
  .value();
＆＃13;
var array = [{
    "mc": {
      "id": "mc-id1"
    },
    "meal": {
      "id": 32,
      "mc_id": "mc-id1",
      "name": "BulletProof Vanilla"
    }
  },
  {
    "mc": {
      "id": "mc-id1",
    },
    "meal": {
      "id": 31,
      "mc_id": "mc-id1",
      "name": "Olive oil"
    }
  },
  {
    "mc": {
      "id": "mc-id2"
    },
    "meal": {
      "id": 38,
      "mc_id": "mc-id2",
      "name": "Organic fish tail"
    }
  },
  {
    "mc": {
      "id": "mc-id2"
    },
    "meal": {
      "id": 37,
      "mc_id": "mc-id2",
      "name": "Organic fish head"
    }
  }
];

var result = _(array)
  // group each item by mc.id key
  .groupBy('mc.id') 
  // associate each mc.id by all of the grouped meals
  .mapValues(_.partial(_.map, _, 'meal')) 
  // convert key-value into an array pair values
  .toPairs()
  // associate the array values into their respective keys
  .map(_.partial(_.zipObjectDeep, ['mc.id', 'meal']))
  // get the value
  .value();
  
console.log(result);
＆＃13;
body > div { min-height: 100%; top: 0; }
＆＃13;
＆＃13;
＆＃13;