如果一个键相同，则创建新的对象数组，然后添加这些对象的其他键值

Question

我想根据一个键过滤掉我的对象数组。 如果该键在其他对象中相同，则将添加对象的第二个值。 我有一个像下面的对象数组：

输入：

var myArray = [
{
_name : "Mike",
_amount : "7"
},
{
_name : "Julius",
_amount : "10"
},
{
_name : "Edison",
_amount : "2"
},
{
_name : "Mike",
_amount : "10"
},
{
_name : "Kate",
_amount : "0"
},{
_name : "Edison",
_amount : "10"
}
]

输出：

var myNewArray = [
{
_name : "Mike",
_amount : "17"
},
{
_name : "Julius",
_amount : "10"
},
{
_name : "Edison",
_amount : "12"
},
{
_name : "Kate",
_amount : "0"
},
]

Mike和Edison重复两次，因此为这些对象添加了_amount键的值。 它对我来说有点困惑。 请帮帮我。 谢谢！

Answer 1

您可以使用Array#forEach和对象作为插入对象的参考。

 var myArray = [{ _name: "Mike", _amount: "7" }, { _name: "Julius", _amount: "10" }, { _name: "Edison", _amount: "2" }, { _name: "Mike", _amount: "10" }, { _name: "Kate", _amount: "0" }, { _name: "Edison", _amount: "10" }], newArray = []; myArray.forEach(function (a) { if (!this[a._name]) { this[a._name] = { _name: a._name, _amount: 0 }; newArray.push(this[a._name]); } this[a._name]._amount = (+this[a._name]._amount + +a._amount).toString(); // if you really }, Object.create(null)); // need strings console.log(newArray); 

按要求按_amount降序排序

 var myArray = [{ _name: "Mike", _amount: "7" }, { _name: "Julius", _amount: "10" }, { _name: "Edison", _amount: "2" }, { _name: "Mike", _amount: "10" }, { _name: "Kate", _amount: "0" }, { _name: "Edison", _amount: "10" }], newArray = []; myArray.forEach(function (a) { if (!this[a._name]) { this[a._name] = { _name: a._name, _amount: 0 }; newArray.push(this[a._name]); } this[a._name]._amount += +a._amount }, Object.create(null)); newArray.sort(function (a, b) { return b._amount - a._amount; }); console.log(newArray); 

Answer 2

就ES6而言，这就是它的完成方式。

 var myArray = [ { _name : "Mike", _amount : "7" }, { _name : "Julius", _amount : "10" }, { _name : "Edison", _amount : "2" }, { _name : "Mike", _amount : "10" }, { _name : "Kate", _amount : "0" },{ _name : "Edison", _amount : "10" } ], result = myArray.reduce((p,c) => {var o = p.find(e => e._name == c._name); !!o ? o._amount = (o._amount*1+c._amount*1)+"" : p.push(c); return p;},[]).sort((a,b) => b._amount-a._amount); console.log(result); 

Answer 3

您要使用的是一个存储键（名称）及其相应数量的地图。 如果您再次遇到密钥，则可以为密钥添加相应的金额。 然后，您可以浏览地图并将对象添加到数组中。

var myArray = [
{
_name:"Mike",
_amount: 7
},
{
_name:"Julius",
_amount: 10
},
{
_name:"Edison",
_amount: 2
},
{
_name:"Mike",
_amount: 10
},
{
_name:"Kate",
_amount: 0
},{
_name:"Edison",
_amount: 10
}
];

var map = {};

for (var i = 0 ; i < myArray.length ; i++) {
    var key = myArray[i]['_name'];
    var amount = myArray[i]['_amount'];
    if (!map[key]) {
        map[key] = amount;
    } else {
        map[key] += amount;
    }
}
var outputArray = [];
for (var key in map) {
    if (map.hasOwnProperty(key)) {
        outputArray.push({_name: key, _amount: map[key]});
    }
}