How to set array key as it's index in javascript/node js

Question

I have an array of objects like this :

var kvArray = [ 
   { 
       number: '123',
       duration: '00:00:00' 
   },
   { 
      number: '324',
      duration: '00:00:00' 
   }]

I want to generate a new array from the above array such that the number key becomes the index.

This is what I tried

var kvArray = [
   { 
       number: '123',
       duration: '00:00:00' 
   },
   { 
       number: '324',
       duration: '00:00:00' 
   }]

var reformattedArray = kvArray.map(obj =>{ 
   var rObj = {};
   rObj[obj.number] = obj.duration;
   return rObj;
});
console.log(reformattedArray)

The above output looks like this in the console with 0 and 1 as the index:

Instead I want the output array to be like this :

123: {"00:00:00"}
324: {"00:00:00"}

such that instead of 0 , 1 as the index I have 123 and 324 as the index. So that if write test_array[123] in my code I should be able to get 00:00:00 in the output. Is it possible to achieve what I'm trying to do here? Suggest better ways how this can be done

How do I do this?

Logically the curly bracket means an object, and you can't create an object without a key. — Kaushik
– Kaushik, Commented Jun 10, 2019 at 5:39

Hassan Imam · Accepted Answer · 2019-06-10 05:44:28Z

4

You can use array#map with Object.assign() to create the desired output.

const data = [ { number: '123', duration: '00:00:00' }, { number: '324', duration: '00:00:00' } ],
      result = Object.assign(...data.map(({number, duration}) => ({[number]: duration})));
      
console.log(result);

answered Jun 10, 2019 at 5:44

Hassan Imam

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3 Comments

briosheje Over a year ago

(side note): keys should be numeric according to the OP's output, so the key should be casted to a number.

Hassan Imam Over a year ago

Keys are meant to be string in an object, if keys are numeric one should use Map.

briosheje Over a year ago

Euuh okay, as you wish, it's just that the answer would be completer in a such a way, to me ;).

Mohammad Usman · Accepted Answer · 2019-06-10 05:41:05Z

3

In case number values will be unique in your array, you can use .reduce() to create a map object like shown below:

const data = [
  { number: '123', duration: '00:00:00' },
  { number: '324', duration: '00:00:00' }
];      
    
const map = data.reduce((r, { number:k, duration:v }) => (r[k] = v, r), {});

console.log(map);

answered Jun 10, 2019 at 5:41

Mohammad Usman

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Comments

dileep nandanam · Accepted Answer · 2019-06-10 06:15:08Z

0

reformattedArray =[]
tempHash = kvArray.reduce(function(i,j){
    return $.extend(i,j)
})
for(i in tempHash) {
    reformattedArray[i] = tempHash[i]
}

answered Jun 10, 2019 at 6:15

dileep nandanam

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