CODEWITHSUNDEEP
javascriptlodash
napi15
napi15

Reputation: 2402

How to return 1 array from 2 arrays based on different properties of each array in lodash?

Lodash v 4.17.15

Let's say I have 2 array 

var users = [{
      id: 12,
      name: Adam
   },{
      id: 14,
      name: Bob
   },{
      id: 16,
      name: Charlie
   },{
      id: 18,
      name: David
   }
]


var jobs = [{
      empid: 12,
      profession: Engineer
   },{
      empid: 14,
      profession: CEO
   },{
      empid: 16,
      profession: CFO
   },{
      empid: 18,
      profession: CTO
   }
]

Expected Result 

var jobsEmp= [{
          empid: 12,
          id: 12,
          name: Adam
          profession: Engineer
       },{
          empid: 14,
          id: 14,
          name: Bob
          profession: CEO
       },{
          empid: 16,
         id: 16,
          name: Charlie
          profession: CFO
       },{
          empid: 18,
          id: 18,
          name: David
          profession: CTO
       }
    ]

I usually do this : 

var jobsEmp =  _.forEach(users, function (emp) {
                    emp.jobs = _.find(jobs, function (jb) {
                        return jb.empid === emp.id;
                    });
                });

But I've noticed that it's not the best way, I've been reading the doc for quite a while, but I just don't know what technique is the best, how to do it properly in lodash?

Upvotes: 0

Views: 67

Answers (2)

Umair Sarfraz
Umair Sarfraz

Reputation: 5953

Without using lodash:

const users = [{
  id: 12,
  name: "Adam"
}, {
  id: 14,
  name: "Bob"
}, {
  id: 16,
  name: "Charlie"
}, {
  id: 18,
  name: "David"
}];


const jobs = [{
  empid: 12,
  profession: "Engineer"
}, {
  empid: 14,
  profession: "CEO"
}, {
  empid: 16,
  profession: "CFO"
}, {
  empid: 18,
  profession: "CTO"
}];

const result = users.map((user) => {
  const job = jobs.find((job) => job.empid === user.id);

  return Object.assign({}, user, job);
});

console.log(result);

Upvotes: 1

Tuan Anh Tran
Tuan Anh Tran

Reputation: 7237

You can do like this but IMO, whatever make it more readable for you and your team. i would prefer method with higher readability 

const _ = require('lodash')

const users = [{
      id: 12,
      name: 'Adam'
   },{
      id: 14,
      name: 'Bob'
   },{
      id: 16,
      name: 'Charlie'
   },{
      id: 18,
      name: 'David'
   }
]


const jobs = [{
      empid: 12,
      profession: 'Engineer'
   },{
      empid: 14,
      profession: 'CEO'
   },{
      empid: 16,
      profession: 'CFO'
   },{
      empid: 18,
      profession: 'CTO'
   }
]

const merged = _.merge(_.keyBy(users, 'id'), _.keyBy(jobs, 'empid'));
const values = _.values(merged);
console.log(values);

output

[ { id: 12, name: 'Adam', empid: 12, profession: 'Engineer' },
  { id: 14, name: 'Bob', empid: 14, profession: 'CEO' },
  { id: 16, name: 'Charlie', empid: 16, profession: 'CFO' },
  { id: 18, name: 'David', empid: 18, profession: 'CTO' } ]

Upvotes: 2

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