javascript - JS(ES6): Merge arrays based on id and concatenating sub arrays

Question

我有两个数组，如下所示:

const persons = [
  {
    id: 1,
    name: 'Peter',
    job: 'Programmer'
  },
  {
    id: 2,
    name: 'Jeff',
    job: 'Architect'
  },
];

const salaries = [
  {
    id: 1,
    salary: 3000,
    departments: ['A', 'B'] 
  },
  {
    id: 1,
    salary: 4000,
    departments: ['A', 'C']
  },
  {
    id: 2,
    salary: 4000,
    departments: ['C', 'D']
  }
];

现在我需要以某种方式将这些数组合并为一个，以便每个 id 只存在一次。应该替换相同的键，除非它是一个数组，然后我希望它们添加/连接。所以想要的结果应该是这样的:

const result = [
  {
    id: 1,
    name: 'Peter',
    job: 'Programmer',
    salary: 4000,
    departments: ['A', 'B', 'C'] 
  },
  {
    id: 2,
    name: 'Jeff',
    job: 'Architect',
    salary: 4000,
    departments: ['C', 'D']
  }
];

我已经尝试过:

// double id's, arrays get replaced
Object.assign({}, persons, salaries)

// loadsh: double id's, arrays get concatenated
_.mergeWith(persons, salaries, (objValue, srcValue) => {
    if (_.isArray(objValue)) {
        return objValue.concat(srcValue);
    }
});

// gives me a map but replaces arrays
new Map(salaries.map(x => [x.id, x])

有人知道如何实现这一目标吗？

Answer 1

您可以使用map() , filter() , reduce() , Object.assign()和 Spread syntax达到所需的结果。

演示

const persons = [{
    id: 1,
    name: 'Peter',
    job: 'Programmer'
  }, {
    id: 2,
    name: 'Jeff',
    job: 'Architect'
  }],
  salaries = [{
    id: 1,
    salary: 3000,
    departments: ['A', 'B']
  }, {
    id: 1,
    salary: 4000,
    departments: ['A', 'C']
  }, {
    id: 2,
    salary: 4000,
    departments: ['C', 'D']
  }];


let output = persons.map(obj => {
  let filter = salaries.filter(v => v.id == obj.id);
  if (filter) {
    let departments = filter.reduce((r, v) => [...v.departments, ...r], []);
    Object.assign(obj, {
      salary: filter[filter.length - 1].salary,
      departments: departments.filter((item, pos) => departments.indexOf(item) == pos).sort()
    });
  }
  return obj;
});

console.log(output)