Merge and reduce multidimensional array of number in JavaScript

Question

I have searched for similar questions on here but the expected result does not meet my needs. Consider the following multidimensional array.

let list = [
   [1,   10,    13,    4],
   [5,   6,    83,    45],
   [9,   18,   11,   12]
];

How would you go about merging all values to produce the following result.

const output = [15, 34, 107, 61];

Jonas Wilms · Accepted Answer · 2018-07-25 12:16:18Z

3

You could reduce the array by adding up the numbers:

 list.reduce((a, b) => a.map((n, i) => n + b[i]))

(This will fail if the arrays got different lengths)

answered Jul 25, 2018 at 12:16

Jonas Wilms

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2 Comments

The good news is that it works, could you give a brief explanation so I can understand why it works?

@jermaine you should read about reduce first, MDN has a good explanation, also this answer might help