获取嵌套object中未知键值的总和

Question

I'm trying to add the total values of Par and Tees, where Tees is a nested object. The values seem to be getting overwritten even though I'm adding to the reduce array. The Par and Handicap are working correctly so it seems the second Object forEach is causing some issues by not looping and saving correctly.

const getTotals = arr => arr.reduce((total, obj) => {
  Object.entries(obj).forEach(([key1, value]) => {
    if (key1 === 'Par') total[key1] = (total[key1] || 0) + value;
    if (key1 === 'Handicap') total[key1] = '-';
    if (key1 === 'tees') {
      Object.entries(obj.tees).forEach(([key2, value]) => {
        total[key1] = {
          [key2]: (obj.tees[key2] || 0) + value
        }
      })
    }
  })
  return total
}, {})

--

let scorecard = [{
    "Hole": 1,
    "Par": 4,
    "tees": {
      "Blue": 372,
      "White": 0,
      "Red_Intermediate": 301,
      "gold": 0
    },
    "Handicap": 10
  },
  {
    "Hole": 2,
    "Par": 4,
    "tees": {
      "Blue": 394,
      "White": 0,
      "Red_Intermediate": 370,
      "gold": 0
    },
    "Handicap": 4
  },
  {
    "Hole": 3,
    "Par": 4,
    "tees": {
      "Blue": 369,
      "White": 0,
      "Red_Intermediate": 248,
      "gold": 0
    },
    "Handicap": 5
  },
  {
    "Hole": 4,
    "Par": 4,
    "tees": {
      "Blue": 361,
      "White": 0,
      "Red_Intermediate": 275,
      "gold": 0
    },
    "Handicap": 18
  },
  {
    "Hole": 5,
    "Par": 4,
    "tees": {
      "Blue": 297,
      "White": 0,
      "Red_Intermediate": 260,
      "gold": 0
    },
    "Handicap": 16
  },
  {
    "Hole": 6,
    "Par": 3,
    "tees": {
      "Blue": 188,
      "White": 0,
      "Red_Intermediate": 167,
      "gold": 0
    },
    "Handicap": 13
  },
  {
    "Hole": 7,
    "Par": 4,
    "tees": {
      "Blue": 342,
      "White": 0,
      "Red_Intermediate": 245,
      "gold": 0
    },
    "Handicap": 12
  },
  {
    "Hole": 8,
    "Par": 3,
    "tees": {
      "Blue": 184,
      "White": 0,
      "Red_Intermediate": 99,
      "gold": 0
    },
    "Handicap": 17
  },
  {
    "Hole": 9,
    "Par": 5,
    "tees": {
      "Blue": 570,
      "White": 0,
      "Red_Intermediate": 452,
      "gold": 0
    },
    "Handicap": 1
  }
]

--

Expected output (estimated values):

let output = [{
  "Par": 35,
  "tees" {
    "Blue": 7200,
    "White": 0,
    "Red_Intermediate": 6300,
    "gold": 0
  },
  "Handicap": '-'
}]

Answer 1

I tried your code it seems you are overwriting the value for 'tees' in each iteration of the second array. here is one way to do it.

const getTotals = arr => arr.reduce((total, obj) => {
    Object.entries(obj).forEach(([key1, value]) => {
        if (key1 === 'Par') total[key1] = (total[key1] || 0) + value;
        if (key1 === 'Handicap') total[key1] = '-';
        if (key1 === 'tees') {
            if (total['tees'] == undefined) {
                total['tees'] = {};
            }
            Object.entries(obj.tees).forEach(([key2, value]) => {
                total['tees'][key2] = (total['tees'][key2] == undefined)?
                   value : total['tees'][key2] + value;
            })
        }
    })
    return total
}, {})

This did give the output in the desired format but the data wasn't the same as what you posted in expected. Below is the output I got and I added the count it matches to the logic (sum of all blue and Red_Intermediate is correct).

{
  Handicap: "-",
  Par: 35,
  tees: {
    Blue: 3077,
    White: 0,
    Red_Intermediate: 2417,
    gold: 0
  }
}