javascript - 对 Javascript 数组内的项目进行分组

Question

我有以下数据结构，我尝试按其父级别对内部部分进行分组。

  const arr = [
    {
      level: '1.1',
      name: 'group title 1',
    },
    {
      level: '1.1.1',
      name: 'group section 1.1.1',
    },
    {
      level: '1.1.2',
      name: 'group section 1.1.2',
    },
    {
      level: '1.1.3',
      name: 'group section 1.1.3',
    },
    {
      level: '1.2',
      name: 'group title 2',
    },
    {
      level: '1.2.1',
      name: 'group section 1.1.1',
    },
    {
      level: '1.3',
      name: 'group title 3',
    },
    {
      level: '1.3.1',
      name: 'group section 1.1.1',
    },
    {
      level: '1.3.2',
      name: 'group section 1.1.2',
    },
    {
      level: '1.4',
      name: 'group title 4',
    },
    {
      level: '1.4.1',
      name: 'group section 1.4.1',
    },
    {
      level: '1.4.2',
      name: 'group section 1.4.2',
    },
    {
      level: '1.4.3',
      name: 'group section 1.4.3',
    },
  ];

我一直在尝试将结构更改为以下对象(对部分进行分组)。该对象具有父级的值作为属性和部分的数组。

  const obj = {
    '1.1': [
      {
        level: '1.1.1',
        name: 'group section 1.1.1',
      },
      {
        level: '1.1.2',
        name: 'group section 1.1.2',
      },
      {
        level: '1.1.3',
        name: 'group section 1.1.3',
      },
    ],
    '1.2': [
      {
        level: '1.2',
        name: 'group title 2',
      },
      {
        level: '1.2.1',
        name: 'group section 1.1.1',
      },
    ],
    '1.3': [
      {
        level: '1.3',
        name: 'group title 3',
      },
      {
        level: '1.3.1',
        name: 'group section 1.1.1',
      },
      {
        level: '1.3.2',
        name: 'group section 1.1.2',
      },
    ],
    '1.4': [
      {
        level: '1.4.1',
        name: 'group section 1.4.1',
      },
      {
        level: '1.4.2',
        name: 'group section 1.4.2',
      },
      {
        level: '1.4.3',
        name: 'group section 1.4.3',
      },
    ],
  };

我的尝试没有成功。对于如何将结构更改为上述结构，我将不胜感激。

Answer 1

Array.prototype.reduce()可用于从数组构造对象。

String.prototype.match()可用于检测字符串中的模式。

/\d+\.\d+/匹配第一次出现的一个或多个数字，后跟一个句号，后跟一个或多个数字

// Input.
const input = [{level: '1.1',name: 'group title 1',},{level: '1.1.1',name: 'group section 1.1.1',},{level: '1.1.2',name: 'group section 1.1.2',},{level: '1.1.3',name: 'group section 1.1.3',},{level: '1.2',name: 'group title 2',},{level: '1.2.1',name: 'group section 1.1.1',},{level: '1.3',name: 'group title 3',},{level: '1.3.1',name: 'group section 1.1.1',},{level: '1.3.2',name: 'group section 1.1.2',},{level: '1.4',name: 'group title 4',},{level: '1.4.1',name: 'group section 1.4.1',},{level: '1.4.2',name: 'group section 1.4.2',},{level: '1.4.3',name: 'group section 1.4.3',},]

// Group.
const group = (array) => array.reduce((o, x) => {
  const key = x.level.match(/\d+\.\d+/)
  if (o[key]) o[key].push(x)
  else o[key] = [x]
  return o
}, {})

// Output.
const output = group(input)

// Proof.
console.log(output)