using underscore _reduce to convert an array to object

Question

How can i convert this array

var array = ['a', 'b', 'c', 'd', 'a', 'b','c', 'd']

to an Object

object = { a:2 , b:2, c:2, d:2 }

using only javascript underscore _reduce ?

Have you tried anything so far? If so, can you please post your attempt? — Nick Parsons, Feb 24 '20 at 09:53
[_.countBy](https://underscorejs.org/#countBy) and please check the docs before asking — Alon Eitan, Feb 24 '20 at 09:55

score 1 · Accepted Answer · answered Feb 24 '20 at 09:59

1


arr.reduce((obj, currentKey) => {
  if(currentKey in obj) {
     obj[currentKey] = obk[currentKey] +1
  } else{ 
    obj[currentKey] = 1
  }

return obj;
}, {});

and testd on your code, here is the output

answered Feb 24 '20 at 09:59

Ahmed Khattab

2,645
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13
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1

FYI - When you're posting an answer, the 7th button from the left (with an icon similar to `<>`) in the editor will allow you to create a working js snippet that will show the output of the code :) – Alon Eitan Feb 24 '20 at 10:03
1

thanks @AlonEitan , im kinda new so now very familiar to these stuff – Ahmed Khattab Feb 24 '20 at 10:27

score 0 · Answer 2 · answered Feb 24 '20 at 09:57

0

I hope this will help

var array = ['a', 'b', 'c', 'd', 'a', 'b','c', 'd'];

var obj = [...new Set(array)]
    .reduce((acc, cur) => ({
      ...acc,
      [cur]: array.filter(item => item === cur).length
    }),
{});

console.log(obj);

answered Feb 24 '20 at 09:57

Jay

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using underscore _reduce to convert an array to object

2 Answers2