CODEWITHSUNDEEP
javascriptobjectfor-loop
e1v1s
e1v1s

Reputation: 385

How to Convert a nested array to an object

I want to create an object from a nested array only 2 levels deep. The function I came up with returns

[{ key1: 'value1', key2: 'value2' }]

rather than

[{ key1: 'value1' }, {key2: 'value2' }]

I've also tried replacing the if statement with obj[elem[0]] = elem[1]; but get the same result.

How can I create separate objects for each nested array?

var array = [["key1", "value1"], ["key2", "value2"]]

function nestedArrToObj(array){

  let obj = {};

  for (let i=0; i < array.length;i++) {
    let elem = array[i];

    if (!(obj[elem[0]])) {
      obj[elem[0]] = elem[1]
    }
  }

  return [obj];
}

Upvotes: 0

Views: 55

Answers (3)

Ele
Ele

Reputation: 33736

Using the function map

let array = [["key1", "value1"], ["key2", "value2"]];
let result = array.map(([key, value]) => ({[key]: value}));

console.log(result)
.as-console-wrapper { max-height: 100% !important; top: 0; }

Using the function reduce

let array = [["key1", "value1"], ["key2", "value2"]];
let result = array.reduce((a, c) => {
  let [key, value] = c;
  return [...a, {[key]: value}];
}, []);

console.log(result)
.as-console-wrapper { max-height: 100% !important; top: 0; }

Cross-browser and backend technology compatible approach:

var array = [["key1", "value1"], ["key2", "value2"]];

var result = [];
for(var a of array) {
  var value = a.pop();
  var key = a.pop();
  
  var object = {};
  object[key] = value;
  
  result.push(object);
}

console.log(result)
.as-console-wrapper { max-height: 100% !important; top: 0; }

Upvotes: 2

גלעד ברקן
גלעד ברקן

Reputation: 23955

Here's a version with map:

console.log(
  [["key1", "value1"], ["key2", "value2"]]
      .map(x => {let obj = {}; obj[x[0]] = x[1]; return obj;})
)

Upvotes: 1

jens
jens

Reputation: 2145

Some of the newer features of the language make this a bit easier. This is an ES5 solution.

var array = [["key1", "value1"], ["key2", "value2"]]

function nestedArrToObj(array){
  return array.reduce(function(previous, current) {
      let obj = {};
      obj[current[0]] = current[1];
      previous.push(obj);
      return previous;
  }, []);
}

console.log(nestedArrToObj(array))

Upvotes: 0

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