Question

这里有很多类似的问题，但是我找不到满足我需求的问题。我正在寻找一个相对简单的解决方案，该解决方案是如何基于键将数组中的对象堆叠到新数组中。

在示例数据中，我们通过“船”键将对象分组。

原始数据：

 var myObjArray = [
    {
        name:'Malcolm Reynolds',
        ship:'Serenity'
    },
    {
        name: 'Carmen Ibanez',
        ship: 'Rodger Young',
    },
    {
        name: 'Zander Barcalow',
        ship: 'Rodger Young',
    },
    {
        name:'Hoban Washburne',
        ship:'Serenity'
    },
    {
        name:'James Kirk',
        ship:'USS Enterprise'
    }
];

重组数据：

    var myNewObjArray = [
    [{
        name:'Malcolm Reynolds',
        ship:'Serenity'
    },
    {
        name:'Hoban Washburne',
        ship:'Serenity'
    }],
    [{
        name: 'Carmen Ibanez',
        ship: 'Rodger Young',
    },
    {
        name: 'Zander Barcalow',
        ship: 'Rodger Young',
    }],
    {
        name:'James Kirk', // optionally also stick in an array
        ship:'USS Enterprise'
    }
];

如果有人对此有解决方案，我将不胜感激，至少可以说，我目前的尝试是草率的。

Answer 1

您可以将对象和ship值用作同一组的键。对于结果，仅获取对象的值。

var data = [{ name: 'Malcolm Reynolds', ship: 'Serenity' }, { name: 'Carmen Ibanez', ship: 'Rodger Young' }, { name: 'Zander Barcalow', ship: 'Rodger Young' }, { name: 'Hoban Washburne', ship: 'Serenity' }, { name: 'James Kirk', ship: 'USS Enterprise' }],
    grouped = Object.values(data.reduce((r, o) => {
        if (!r[o.ship]) {
            r[o.ship] = o;
            return r;
        }
        if (!Array.isArray(r[o.ship])) r[o.ship] = [r[o.ship]];
        r[o.ship].push(o);
        return r;
    }, {}));

console.log(grouped);

.as-console-wrapper { max-height: 100% !important; top: 0; }

使用Map

的方法

var data = [{ name: 'Malcolm Reynolds', ship: 'Serenity' }, { name: 'Carmen Ibanez', ship: 'Rodger Young' }, { name: 'Zander Barcalow', ship: 'Rodger Young' }, { name: 'Hoban Washburne', ship: 'Serenity' }, { name: 'James Kirk', ship: 'USS Enterprise' }],
    grouped = Array.from(
        data
            .reduce((m, o) => m.set(o.ship, [...(m.get(o.ship) || []), o]), new Map)
            .values(),
        a => a.length === 1 ? a[0] : a
    );

console.log(grouped);

.as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 2

查找和删除重复的船舶名称，然后为每艘船舶找到人员。

const myObjArray = [
    {
        name:'Malcolm Reynolds',
        ship:'Serenity'
    },
    {
        name: 'Carmen Ibanez',
        ship: 'Rodger Young',
    },
    {
        name: 'Zander Barcalow',
        ship: 'Rodger Young',
    },
    {
        name:'Hoban Washburne',
        ship:'Serenity'
    },
    {
        name:'James Kirk',
        ship:'USS Enterprise'
    }
];

const ships = myObjArray.map(({ship}) => ship).filter((ship, i, arr) => arr.indexOf(ship) === i);

const personnelArray = ships.map(ship => myObjArray.filter(entry => entry.ship === ship));

console.log(personnelArray);

Answer 3

另一种干净优雅的解决方案将与Lodash一起使用。

首先，使用相关键对数组进行分组。然后，从对象中获取值。

从文档中：

创建一个由键组成的对象，这些键由通过iteratee运行collection每个元素的结果生成。分组值的顺序由它们在集合中出现的顺序决定。每个密钥的对应值是负责生成密钥的元素数组。使用一个参数（值）调用iteratee。

const  myObjArray = [
{
    name:'Malcolm Reynolds',
    ship:'Serenity'
},
{
    name: 'Carmen Ibanez',
    ship: 'Rodger Young',
},
{
    name: 'Zander Barcalow',
    ship: 'Rodger Young',
},
{
    name:'Hoban Washburne',
    ship:'Serenity'
},
{
    name:'James Kirk',
    ship:'USS Enterprise'
}
];

var result =_.values((_.groupBy(myObjArray , 'ship')));

console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.16.4/lodash.min.js"></script>

Answer 4

可能不是表现最好的，但是应该可以。

var tempObj = {};
myObjArray.forEach((item)=>{
  var ship = item.ship;
  if (!tempObj.hasOwnProperty(ship)) {
    tempObj[ship] = []; //create the key in the key in the obj and init to an empty array
  }
  tempObj[ship].push(item); //add the item to the array
});

var myNewObjArray = [];

for (key in tempObj) {
  myNewObjArray.push([]); //add a new array for each key in the tempObj
  tempObj[key].forEach((item)=>{ //iterate over the array of items in the tempObj for that key
    myNewObjArray[myNewObjArray.length-1].push(item); //add the item to the last array in the object which should have been created.
  });
}

Answer 5

不知道您打算如何使用数据，但是更简洁的数据结构看起来像一个对象，其中船上有人员，而不是一个以冗余方式不断重复出现的船名数组？那么这个数据结构呢？

var myObjArray = [
    {
        name:'Malcolm Reynolds',
        ship:'Serenity'
    },
    {
        name: 'Carmen Ibanez',
        ship: 'Rodger Young',
    },
    {
        name: 'Zander Barcalow',
        ship: 'Rodger Young',
    },
    {
        name:'Hoban Washburne',
        ship:'Serenity'
    },
    {
        name:'James Kirk',
        ship:'USS Enterprise'
    }
];

const staffShips = data => data.reduce((ships, item) => {
  const ship = ships[item.ship];
  if (ship) {
    ship.push(item.name);
  } else {
    ships[item.ship] = [ item.name ];
  }
  return ships;
}, {});

console.log(staffShips(myObjArray));

Answer 6

这有点不同，因为它是一个带有键的对象，但是这些键包含具有数据的数组，您希望如何查看它。

var newObject = {};

for (var i in myObjArray) {
     var newKey = myObjArray[i].ship.replace(/\s+/g, '');
   if (typeof(newObject[newKey]) == "undefined") newObject[newKey] = [];
   newObject[newKey].push({
        name: myObjArray[i].name, ship: myObjArray[i].ship
   });
}

Answer 7

这里有另一种方法，首先，我们使用Array.reduce()生成一个对象，该对象将按ship属性对元素进行分组。然后，如果仅包含一个元素，则在生成的Array.map()上使用Object.values()来删除数组。如果您真的不需要最后一步，则该地图可能是可选的。

npm i -g npm

var myObjArray = [
  {name:'Malcolm Reynolds', ship:'Serenity'},
  {name: 'Carmen Ibanez', ship: 'Rodger Young'},
  {name: 'Zander Barcalow', ship: 'Rodger Young'},
  {name:'Hoban Washburne', ship:'Serenity'},
  {name:'James Kirk', ship:'USS Enterprise'}
];

let res = myObjArray.reduce((acc, obj) =>
{
    acc[obj.ship] = acc[obj.ship] || [];
    acc[obj.ship].push(obj);
    return acc;
}, {});

res = Object.values(res).map(arr => (arr.length <= 1 ? arr[0] : arr));

console.log(res);

Answer 8

在Javascript中，要按属性对对象进行分组，可以使用Array.prototype.reduce（）方法将输入数组数据合并为一组结果，并按一个键（在本例中为“ ship”）进行分组。通过拖放键，使用Object.values从结果集中提取值

var data = [
{ name: 'Malcolm Reynolds', ship: 'Serenity' },
{ name: 'Carmen Ibanez', ship: 'Rodger Young' }, 
{ name: 'Zander Barcalow', ship: 'Rodger Young' }, 
{ name: 'Hoban Washburne', ship: 'Serenity' }, 
{ name: 'James Kirk', ship: 'USS Enterprise' }];

var myNewObjArray = data.reduce((res,obj) =>{
const key = obj.ship;
if(!res[key]){
res[key] = [];
}
res[key].push(obj)
return res;
}, {});

console.log(Object.values(myNewObjArray));

通过对象数组中的键创建对象数组

8 个答案: