Change objects in nested structure using map function

Question

I am trying to change objects in nested map functions. I have one array of objects with nested data.

If I try to do on this way structure of data is changing. I'm getting array of arrays. Only what I need here is to add for each object one property "level". Is it possible to do this with nested map functions?

const res = data.map(itemA => ({ ...itemA,
    level: 'a'
  })
  .subA.map(itemB => ({ ...itemB,
    level: 'b'
  })))

console.log(res)

<script>
  let data = [{
      name: 'testA1',
      subA: [{
          name: 'testB1',
          subB: [{
            name: 'testC1',
            subC: []
          }]
        },
        {
          name: 'testB2',
          subB: [{
            name: 'testC1',
            subC: []
          }]
        }
      ]
    },
    {
      name: 'testA2',
      subA: [{
        name: 'testB1',
        subB: [{
          name: 'testC1',
          subC: [{
            name: 'testD1',
            subD: []
          }]
        }]
      }]
    }
  ]
</script>

Could you provide an example on what the result for your example shall look like? — Malte
– Malte, Commented Dec 13, 2021 at 20:23

MWO · Accepted Answer · 2021-12-13 21:26:41Z

1

You can use a recursive function?

let data = [{ name: 'testA1', subA: [{ name: 'testB1', subB: [{ name: 'testC1', subC: [] }] }, { name: 'testB2', subB: [{ name: 'testC1', subC: [] }] } ] }, { name: 'testA2', subA: [{ name: 'testB1', subB: [{ name: 'testC1', subC: [{ name: 'testD1', subD: [] }] }] }] } ]

function addprop(arr, level){
    arr.map(x=>{
        const match = Object.keys(x).find(element => {
            if (element.includes('sub')) {
              return true;
            }
          });
          addprop(x[match], level+1)
    })
    return arr.map(x=>(x.level=level,x))
}

console.log(addprop(data, 1))

edited Dec 13, 2021 at 21:26

answered Dec 13, 2021 at 21:12

MWO

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Comments

mplungjan · Accepted Answer · 2021-12-14 18:28:36Z

0

Actually I did it on this way:

const res = data.map(itemA => (
  {...itemA, level: 'a', subA: itemA.subA.map(itemB => (
    {...itemB, level: 'b', subB: itemB.subB.map(itemC => (
      {...itemC, level: 'c'}
    ))}
  ))}
))
console.log(res)

<script>
  let data = [{
      name: 'testA1',
      subA: [{
          name: 'testB1',
          subB: [{
            name: 'testC1',
            subC: []
          }]
        },
        {
          name: 'testB2',
          subB: [{
            name: 'testC1',
            subC: []
          }]
        }
      ]
    },
    {
      name: 'testA2',
      subA: [{
        name: 'testB1',
        subB: [{
          name: 'testC1',
          subC: [{
            name: 'testD1',
            subD: []
          }]
        }]
      }]
    }
  ]
</script>

edited Dec 14, 2021 at 18:28

mplungjan

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answered Dec 13, 2021 at 20:23

kasp3rsky

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2 Comments

Community Over a year ago

Your answer could be improved with additional supporting information. Please edit to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center.

MWO Over a year ago

your answer only works to level c

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