需要帮助获取数组中对象长度的值答案

【问题标题】：Need help getting the value of object length in array需要帮助获取数组中对象长度的值
【发布时间】：2021-02-25 21:17:05
【问题描述】：

我有一个看起来像这样的数组。

0: Object { age: 1.22128, initials: "YY", major: "Internet Content & Information" }

1: Object { age: 0.623491, initials: "RAM", major: "Banks Diversified" }

2: Object { age: 3.47226, initials: "W", major: "Internet Retail" }

3: Object { age: 0.10981, initials: "DAM", major: "Communication Equipment" }

4: Object { age: 0, symbol: initials", major: "Software Application" }

5: Object { age: 0.82384, initials: "SAM", major: "Internet Content & Information" }

6: Object { age: 1.62574, initials: "LISA", major: "Internet Content & Information" }

7: Object { age: 0, initials: "AN", college: "major Content & Information" }

8: Object { age: 1.34786, initials: "PAM", major: "REIT Retail" }

9: Object { age: 0, initials: "DREW", major: "Software—Infrastructure" }

我想做的是把专业分类成一个图表，我可以使用这段代码来做到这一点。下面。

      var data = array, 
  result = _(data)
  .groupBy('major')
  .map((group, major) => 
      ({ industry, children: _.map(group, ({ initials: major, age }) => ({ major, age })) }))
  .value(),
// final = [{ name: "Children Array", children: result }];
final = result

我用来将首字母分配给专业的图表采用这样的值。

  const data = [
  {
    type: 'Retail',
    value: 38,
  },
  {
    type: 'Software',
    value: 5,
  },
  {
    type: 'Engineering',
    value: 35,
  },
  {
    type: 'Real Estate',
    value: 15,
  },
  {
    type: 'HealthCare',
    value: 7,
  },
]

使用上面的代码摘录，我能够将它放在一个看起来像这样的数组中。

(18) […]

0: Object { major: "Internet Content & Information", children: (5) […] }

1: Object { major: "Banks Diversified", children: (1) […] }

2: Object { major: "Internet Retail", children: (1) […] }

3: Object { major: "Communication Equipment", children: (2) […] }

4: Object { major: "Software Application", children: (3) […] }

孩子们指出该专业中有多少个首字母，有没有办法可以创建一个新数组来模仿图表在代码中的方式，这样我就可以将专业作为类型，将孩子的值作为值在图表中。

如果有人可以帮助我将顶部的数组转换为图表的数据语法，我也会很高兴。谢谢你

【问题讨论】：

标签： javascript node.js arrays json object

【解决方案1】：

您可以首先创建带有键的对象作为所有主要元素，然后循环通过它来创建您想要的数组见下sn-p

const input = [
  { age: 1.22128, initials: "YY", major: "Internet Content & Information" },
  { age: 0.623491, initials: "RAM", major: "Banks Diversified" },
  { age: 3.47226, initials: "W", major: "Internet Retail" },
  { age: 0.10981, initials: "DAM", major: "Communication Equipment" },
  { age: 0, initials: "SHA", major: "Software Application" },
  { age: 0.82384, initials: "SAM", major: "Internet Content & Information" },
  { age: 1.62574, initials: "LISA", major: "Internet Content & Information" },
  { age: 0, initials: "AN", major: "major Content & Information" },
  { age: 1.34786, initials: "PAM", major: "REIT Retail" },
  { age: 0, initials: "DREW", major: "Software—Infrastructure" },
];

const obj = {};
input.forEach((row) => {
  if (!obj[row.major]) obj[row.major] = 1;
  obj[row.major]++;
});
const output = [];
for (var key in obj) {
  output.push({ type: key, value: obj[key] });
}
console.log(output);

【讨论】：