Add Up Variables in JavaScript Array

Question

Hi I have a JavaScript array, which looks something like the following.

{x: red, y: 2}
{x: blue, y: 3}
{x: blue, y; 4}
{x: green, y: 5}

My question is, how to add up the dupilicates, so in the end my array looks like the code below.

Also could the process be done in a loop since I actually have a much larger amount of data to format this way.

{x: red, y: 2}
{x: blue, y: 7} #the two blue y variables have been added
{x: green, y: 5}

Alternative duplicate: [How to group by and sum an array of objects?](https://stackoverflow.com/questions/29364262/how-to-group-by-and-sum-an-array-of-objects) — Ivar, Jul 15 '21 at 16:38

Spectric · Accepted Answer · 2021-07-15T16:34:02.423

0

Try:

var xs = [];

const data=[{x:"red",y:2},{x:"blue",y:3},{x:"blue",y:4},{x:"green",y:5}];

var n = []
data.forEach((e) => {
  if (!xs.includes(e.x)) { n.push(e); xs.push(e.x) }
  else { n.forEach(f => f.y += f.x == e.x ? e.y : 0) }
})

console.log(n);

edited Jul 15 '21 at 16:34

answered Jul 15 '21 at 16:29

Spectric

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Thanks for your help, unfortunately the code doesnt add up the second variable, it only pushes the first occurence of blue. in the end it show blue and 3 instead of blue and 7 – sppokky Jul 15 '21 at 16:30
@luthienaerendell I've updated my answer. It should work now. – Spectric Jul 15 '21 at 16:34
yes it does! thanks so much for your help – sppokky Jul 15 '21 at 16:37

Add Up Variables in JavaScript Array

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