Flatten an array of objects into a single array

Question

I have an array of an object with dynamic keys

response = [{"1": 1}, {"2": 1}, {"3": 1}, {"4": 0}, {"5": 0}];

I want to flatten this array of an object into a single array

Output = [1, 1, 1, 0, 0]

I tried the following:

const test2 = this.response.map(obj => {
    Object.keys(obj).map(function(key){
        return obj[key]
    })
});

const test = this.response.reduce(function(prev, curr){
    console.log(curr)
    return (curr) ? prev.concat(curr): prev;
},[]);

epascarello · Accepted Answer · 2018-09-10 18:02:33Z

7

You can just use map and object.values

response = [{"1": 1}, {"2": 1}, {"3": 1}, {"4": 0}, {"5": 0}]
const vals = response.map(o => Object.values(o)[0])

console.log(vals)

answered Sep 10, 2018 at 18:02

epascarello

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2 Comments

Yzak Over a year ago

Type '{}[]' is not assignable to type 'number[]'. when used on the chart but works perfect on the concept

epascarello Over a year ago

No clue why that error would occur with that code above.

Mohammad Usman · Accepted Answer · 2018-09-10 18:02:59Z

5

You can use .map() with .concat():

let data =   [{"1": 1}, {"2": 1}, {"3": 1}, {"4": 0}, {"5": 0}];
      
let result = [].concat(...data.map(Object.values));

console.log(result);

answered Sep 10, 2018 at 18:02

Mohammad Usman

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Comments

brk · Accepted Answer · 2018-09-10 18:05:23Z

1

Use reduce and for..in to loop over the object

let response = [{
    "1": 1
  },
  {
    "2": 1
  },
  {
    "3": 1
  },
  {
    "4": 0
  },
  {
    "5": 0
  }
]

let k = response.reduce(function(acc, curr) {
  for (let keys in curr) {
    acc.push(curr[keys])

  }
  return acc;
}, [])
console.log(k)

answered Sep 10, 2018 at 18:05

brk

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Comments

michaelitoh · Accepted Answer · 2018-09-10 18:07:10Z

1

response = [{"1": 1},{"2": 1},{"3": 1},{"4": 0},{"5": 0}]

var newArray = []
for (element of response) {
  Object.keys(element).map(key => {
    newArray.push(element[key])
  })
}


console.log(newArray)

answered Sep 10, 2018 at 18:07

michaelitoh

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