Group By array of objects and calculate total for key value

Question

I've got an array of objects:

let recipe = [
  {
    Type:"AAAA",
    Total: 20
  },
  {
    Type:"BBBB",
    Total: 20,
  },
  {
    Type:"BBBB",
    Total: 20,
  },
  {
    Type:"AAAA",
    Total: 20,
  },
  {
    Type:"AAAA",
    Total: 20,
  }
]

And I want to get, using javascript (no libraries), the final form like this:

let finalRecipe = [["AAAA",60],["BBBB",40]]

I tried to used this but not working

let recipeModified = recipe.reduce((r, timeoff) => {
  const { Type, Total } = timeoff;
  const totalSum = Object.values({
    Total,
  }).reduce((acc, val) => ([...acc, ...val], []));

  r[Type] = [...(r[Type] || []), totalSum];

  return r;
}, {})

https://codesandbox.io/s/cranky-ishizaka-i7m6v?file=/src/index.js

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@Daniyal Lukmanov I tried but I can't figure it out how to make it work — Dazzy, Aug 31 '20 at 09:04
This question has been asked so many times before... A little bit of research would be welcome. — trincot, Aug 31 '20 at 09:04

score 1 · Accepted Answer · answered Aug 31 '20 at 09:03

You can use the function Array.prototype.reduce for grouping the objects by Type and the function Object.values to extract the grouped objects.

let recipe = [  {    Type:"AAAA",    Total: 20  },  {    Type:"BBBB",    Total: 20,  },  {    Type:"BBBB",    Total: 20,  },  {    Type:"AAAA",    Total: 20,  },  {    Type:"AAAA",    Total: 20,  }],
    result = Object.values(recipe.reduce((r, {Type, Total}) => {
      (r[Type] || (r[Type] = [Type, 0]))[1] += Total;
      return r;
    }, {}));

console.log(result);

Group By array of objects and calculate total for key value

1 Answers1