javascript - 对象数组中属性值的递归数组

Question

我需要的是一个属性值数组，从一个对象数组中递归收集，这就是我的意思:

const regions = [{
  name: 'Europe',
  subRegions: [{
    name: 'BeNeLux',
    territories: [{
      code: 'NL',
      name: 'Netherlands'
    }, {
      code: 'DE',
      name: 'Germany'
    }, {
      code: 'LU',
      name: 'Luxembourgh'
    }]
  }],
  territories: [{
    code: 'UK',
    name: 'United Kingdom'
  }, {
    code: 'AL',
    name: 'Albania'
  }, {
    code: 'ZW',
    name: 'Switzerland'
  }]
}]

我想获取 regions 数组中所有国家/地区代码的数组。

就像:

const expectedOutput = ['NL', 'DE', 'LU', 'AL', 'ZW', 'UK'];

这是我尝试过的方法，它部分有效但没有正确收集(我也很好奇探索不同/功能设置来解决这个问题)

const getAllTerritoryCodesFromRegions = regions => {
  return regions
    .reduce(function r (output, region) {
      if (region?.subRegions?.length) {
        output.subRegions = region.subRegions.reduce(r, output)
      }

      if (region?.territories?.length) {
        output = [
          ...output,
          ...region.territories.map(t => t.code)
        ]
      }

      return output
    }, [])
}

Answer 1

您可以通过查找数组并返回代码来减少数组。

function getCodes(array) {
    return array.reduce((r, o) => {
        if ('code' in o) {
            r.push(o.code);
            return r;
        }
        Object.values(o).forEach(v => {
            if (Array.isArray(v)) r.push(...getCodes(v));
        });
        return r;
    }, []);
}

const
    regions = [{ name: 'Europe', subRegions: [{ name: 'BeNeLux', territories: [{ code: 'NL', name: 'Netherlands' }, { code: 'DE', name: 'Germany' }, { code: 'LU', name: 'Luxembourgh' }] }], territories: [{ name: 'United Kingdom', code: 'UK' }, { name: 'AL', code: 'Albania' }, { name: 'ZW', code: 'Switzerland' }] }],
    codes = getCodes(regions);

console.log(codes);