Javascript: 通过 lodash 或下划线或 corejavascript 转换对象响应数组

Question

我正在使用 highChart 创建柱形图。我如何通过与数据库通信来创建以下 arrayofObj。

现在，我需要将以下 source 对象数组转换为以下输出。

var source = [
{data: 258, name: '2014'}
{data: 18, name: '2016'}
{data: 516, name: '2014'}
{data: 0, name: '2014'}
{data: 354, name: '2014'}
{data: 18, name: '2016'}
]`

将此对象数组转换为

Output

[{
    name: '2014',
    data: [258, 516, 354]
  }, {
    name: '2016',
    data: [18, 0, 18]
}]

基本上，我希望我的数组按名称（年份）分组并且数据应该在数组中

这是我应用的解决方案。

var source = [];
_.each(source, function(singlerec) {
      source.push({
        name: singlerec.name,
        data: singlerec.data  // Here It only assign single record
      });
    });

Answer 1

在Lodash中，我总是使用_.groupBy and then _.map输出格式。

var source = [{"data":258,"name":"2014"},{"data":18,"name":"2016"},{"data":516,"name":"2014"},{"data":0,"name":"2014"},{"data":354,"name":"2014"},{"data":18,"name":"2016"}];

var output = _(source)
  .groupBy('name')
  .map(function(v, k) { return { name: k, data: _.map(v, 'data') } })
  .value();

console.log(output);

<script src="https://cdn.jsdelivr.net/lodash/4.13.1/lodash.min.js"></script>

Answer 2

有一种方法可以使用 reduce 甚至不用 lodash 来迭代数组一次。

source.reduce((p, n) => {
    (p[n.name] || (p[n.name] = [])).push(n.data);
    return p
}, {})

Answer 3

我使用纯 javascript 函数：

const pick = (obj, paths) => ({...paths.reduce((a, k) => ({...a, [k]: obj[k]}), {})})

function groupByAndConcat(data, groupBy, sums) {
    return data.reduce((results, r) => {
        const e = results.find((x) => groupBy.every((g) => x[g] === r[g]));
        if (e) {
            sums.forEach((k) => e[k] = [].concat(e[k], r[k]));
        } else {
            results.push(pick(r, groupBy.concat(sums)));
        }
        return results;
    }, []);
}

鉴于您的示例来源：

const source = [
    {data: 258, name: '2014'},
    {data: 18, name: '2016'},
    {data: 516, name: '2014'},
    {data: 0, name: '2014'},
    {data: 354, name: '2014'},
    {data: 18, name: '2016'},
];

console.log(groupByAndConcat(source, ["name"], ["data"]))

输出：

[{ name: "2014", data: Array [258, 516, 0, 354] }, { name: "2016", data: Array [18, 18] }]

也可以对几个props进行分组或操作：

groupByAndConcat(source, ["name","month"], ["data","data2"])

Javascript: 通过 lodash 或下划线或 corejavascript 转换对象响应数组

Javascript: Transform array of object response via lodash or underscore or corejavascript

javascript

underscore.js

lodash