将具有相同属性的多个对象转换为单个对象 object - Javascript

Question

I couldn't find a good example or any resources on how to actually transform multiple objects that contain the same property ( fullName ) in my case and how to make only 1 object with the following structure (in order to work on just 1 object instead of multiple)

The sample objects look like this:

{
  fullName: 'Reuben Daly',
  from: '2015-06-01',
  to: '2016-07-01',
  companyName: 'Mondelēz International'
}
{
  fullName: 'Reuben Daly',
  from: '2017-04-01',
  to: '2017-12-01',
  companyName: 'Redgate Software'
}
{
  fullName: 'Reuben Daly',
  from: '2013-10-01',
  to: '2014-01-01',
  companyName: 'Cambridge International Examinations'
}
...

and the goal is to create 1 object that is actually containing all of the values stored in 1, like this:

{
  fullName: 'Reuben Daly',
  pos1from: '2015-06-01',
  pos1to: '2016-07-01',
  pos1companyName: 'Mondelēz International',
  pos2from: '2017-04-01',
  pos2to: '2017-12-01',
  pos2companyName: 'Redgate Software'
  pos3from: '2013-10-01,
  pos3to: '2014-01-01',
  pos3companyName: 'Cambridge International Examinations'
  ...

}

I have been trying to achieve that with reduce() but as I'm having objects instead of arrays it won't work. Been reading about the forEach() method but can't find a good example that is actually doing something similar and I've stuck.

Answer 1

You should use an object as initial value in reduce:

const data=[
    {
  fullName: 'Reuben Daly',
  from: '2015-06-01',
  to: '2016-07-01',
  companyName: 'Mondelēz International'
},
{
  fullName: 'Reuben Daly',
  from: '2017-04-01',
  to: '2017-12-01',
  companyName: 'Redgate Software'
},
{
  fullName: 'Reuben Daly',
  from: '2013-10-01',
  to: '2014-01-01',
  companyName: 'Cambridge International Examinations'
},
]

const result =  data.reduce((acc,elem, index)=>({
        ...acc,
        fullName:elem.fullName,
        [`from${index+1}`]:elem.from,
        [`to${index+1}`]:elem.to,
        [`companyName${index+1}`]:elem.companyName
    }   ),{})

Answer 2

 const arr = [{ fullName: 'Reuben Daly', from: '2015-06-01', to: '2016-07-01', companyName: 'Mondelēz International' }, { fullName: 'Reuben Daly', from: '2017-04-01', to: '2017-12-01', companyName: 'Redgate Software' }, { fullName: 'Reuben Daly', from: '2013-10-01', to: '2014-01-01', companyName: 'Cambridge International Examinations' }]; const result = arr.reduce((acc, cur, i) => { if (i === 0) { acc = {fullName: cur.fullName}; } ["from", "to", "companyName"].forEach(attr => { acc[`pos${i + 1}${attr}`] = cur[attr]; }); return acc; }, {}); console.log(result);

Answer 3

First put all those objects into an array.

const objArr = [o1,o2,o3]; etc. 

What you can do from here is iterate over the objects and then within that loop nest a second loop that will iterate over the keys of each object. You can modify the key, providing it isn't the fullName key or one whose value you know will not change, for the new object that will accumulate all the properties.

const newObj = {o1.fullName};  
for(let i = 0; i < objArr.length; i++){
    let o = objArr[i]; 
    for(let key in o){
        if(key !== 'fullName'){
            let newKey = 'pos' + (i + 1) + key;
            newObj[newKey] = o[key]; 
        }
    }
}