Question

我正在尝试通过传递我想要分组的键来分组对象数组作为我写的函数的参数，例如，如果我有3个对象的数组：

[{date: "2018-01-01", website: "example.com", revenue: 100},
 {date: "2018-01-01", website: "example2.com", revenue:200},
 {date: "2018-01-02", website: "example.com", revenue: 300}]

我将把它们传递给我的函数：

    groupArr(arr, prop) {
        return arr.reduce(function (groups, item) {
            const val = item[prop];
            groups[val] = groups[val] || [];
            groups[val].push(item);
            return groups
        }, {})
    }

结果将是：{2018-01-01: Array(2), 2018-01-02: Array(1)}

但现在我想弄清楚如何更改此功能，我可以传递两个参数，例如日期和网站：groupArr(arr,["date","website"] 所以我的结果将包括两个参数组，在我的情况下最终会像这样：

{{[2018-01-01,"example.com"]: Array(1),[2018-01-01,"example2.com"]: Array(1), 2018-01-02: Array(1)}

为了方便起见，我将结果键呈现为数组，不确定这是否是正确的方法。任何想法我怎么能实现这一目标？感谢

Answer 1

您可以创建一个由所需属性的值组成的新密钥。

＆＃13;

function groupArr(arr, ...props) {
    return arr.reduce(function (groups, item) {
        const key = props.map(k => item[k]).join('|');
        groups[key] = groups[key] || [];
        groups[key].push(item);
        return groups;
    }, {});
}
var array = [{ date: "2018-01-01", website: "example.com", revenue: 100 },  {date: "2018-01-01", website: "example2.com", revenue: 200 }, { date: "2018-01-02", website: "example.com", revenue: 300 }, { date: "2018-01-01", website: "example.com", revenue: 340 }];
    grouped = groupArr(array, "date", "website");

console.log(grouped);

＆＃13;

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

＆＃13;

Answer 2

您可以执行以下操作：

＆＃13;

let arr = [{date: "2018-01-01",website: "example.com",revenue: 100},{date: "2018-01-01",website: "example2.com",revenue: 200},{date: "2018-01-02",website: "example.com",revenue: 300}];


function groupArr(arr, prop) {
  prop = Array.isArray(prop) ? prop : [prop];         //Make sure that prop is an array. Convert to array if not

  return arr.reduce(function(groups, item) {
    const val = prop.map(o => item[o]).join('-');     //Map and Concat all values of prop and use as key

    groups[val] = groups[val] || [];
    groups[val].push(item);
    return groups
  }, {})
}

//Will work if prop is array
let result = groupArr(arr, ["date", "website"]);
console.log(result);

//Will work if string
let result2 = groupArr(arr, "date");
console.log(result2);

＆＃13;

通过多个参数对对象组进行分组

2 个答案: