如何转换映射：将值转为键并合并关联值为数组存入对应键

需求说明 #

整合三组数据，将names数组中的name字段作为对象键，把关联的phoneNumbers中的phoNumb字段整理为数组存入对应键，最终得到指定格式的结果。

原始数据 #

const names= [
  { id: 1, name: 'JULIO FONTOVA' },
  { id: 2, name: 'CHRISTIAN JONES' },
  { id: 3, name: 'MARK DAVIES' }
];

const nexus = [
  { namesId: 1, phoNumbId: 1, country: 'PERU', mount: 1200 },
  { namesId: 1, phoNumbId: 2, country: 'CANADA', mount: 2000},
  { namesId: 2, phoNumbId: 2, country: 'ENGLAND', mount: 3000},
  { namesId: 2, phoNumbId: 3, country: 'RUSSIA', mount: 40000},
  { namesId: 3, phoNumbId: 1, country: 'BELGIUM', mount: 500},
  { namesId: 3, phoNumbId: 2, country: 'SPAIN', mount: 500},
  { namesId: 3, phoNumbId: 3, country: 'PORTUGAL', mount: 2020}
]

const phoneNumbers= [
  { id: 1, phoNumb: '111', name: 'JHON EVANS'},
  { id: 2, phoNumb: '222', name: 'JUDITH SOTO'},
  { id: 3, phoNumb: '333', name: 'OSCAR CIENFUEGOS'},
  { id: 4, phoNumb: '444', name: 'ANDREW JONES'}
]

目标结果 #

const mergedNumbers = [
  {'JULIO FONTOVA': ['111', '222']},
  {'CHRISTIAN JONES': ['222', '333']},
  {'MARK DAVIES': ['111', '222', '333']}
]

实现代码 #

// 建立nameId与name的映射表
const nameMap = new Map(names.map(item => [item.id, item.name]));
// 建立phoneId与phoNumb的映射表
const phoneMap = new Map(phoneNumbers.map(item => [item.id, item.phoNumb]));

// 按姓名分组收集电话号码
const groupedData = {};
nexus.forEach(entry => {
  const userName = nameMap.get(entry.namesId);
  const userPhone = phoneMap.get(entry.phoNumbId);
  
  if (!groupedData[userName]) {
    groupedData[userName] = [];
  }
  // 避免重复添加同一号码
  if (!groupedData[userName].includes(userPhone)) {
    groupedData[userName].push(userPhone);
  }
});

// 转换为目标数组格式
const mergedNumbers = Object.entries(groupedData).map(([name, phones]) => ({ [name]: phones }));

console.log(mergedNumbers);

代码说明 #

• 用Map构建id与对应值的映射，减少数组遍历次数，提升处理效率
• 遍历关联表nexus，通过映射表快速匹配姓名和电话号码，完成分组收集
• 最后将分组后的对象转换为目标数组结构，每个元素为单独的键值对对象

内容的提问来源于stack exchange，提问作者MarcoPavez