Filtering Array of Objects into multiple array of objects based on property

Question

Currently, I have an array of objects

const bankData = [
    {
      "bank": "Chase",
      "monthEndBalance": "72,175.88",
      "bankStatementDate": "2020/10/31"
    },
    {
      "bank": "Chase",
      "monthEndBalance": "93,412.79",
      "bankStatementDate": "2020/07/31"
    },
    {
      "bank": "Chase",
      "monthEndBalance": "88,175.88",
      "bankStatementDate": "2020/11/30"
    },
    {
      "bank": "Chase",
      "monthEndBalance": "102,200.12",
      "bankStatementDate": "2020/12/31"
    },
    {
      "bank": "Goldman Sachs",
      "monthEndBalance": "72,276.12",
      "bankStatementDate": "2020/11/30"
    },
    {
      "bank": "Goldman Sachs",
      "monthEndBalance": "52,276.12",
      "bankStatementDate": "2020/10/31"
    },
    {
      "bank": "Goldman Sachs",
      "monthEndBalance": "102,276.12",
      "bankStatementDate": "2020/12/31"
    },
    {
      "bank": "Wells Fargo",
      "monthEndBalance": "33,276.12",
      "bankStatementDate": "2020/11/30"
    },
    {
      "bank": "Wells Fargo",
      "monthEndBalance": "12,276.12",
      "bankStatementDate": "2020/10/31"
    },
    {
      "bank": "Wells Fargo",
      "monthEndBalance": "150,276.12",
      "bankStatementDate": "2020/12/31"
    }
]

I'm looking for the desired output where each bank will be filtered out into it's own array of objects.

E.g


const bankOne = [
    {
      "bank": "Chase",
      "monthEndBalance": "72,175.88",
      "bankStatementDate": "2020/10/31"
    },
    {
      "bank": "Chase",
      "monthEndBalance": "93,412.79",
      "bankStatementDate": "2020/07/31"
    },
    {
      "bank": "Chase",
      "monthEndBalance": "88,175.88",
      "bankStatementDate": "2020/11/30"
    },
    {
      "bank": "Chase",
      "monthEndBalance": "102,200.12",
      "bankStatementDate": "2020/12/31"
    }
]

I have a rudimentary implementation with Array.filter that does it but it is not scalable as more banks are added and it would require a code change for each new bank, what would be the ideal method that's able to filter each bank into its own unique array of objects?

const chaseBank = bankData.filter(el => el.bank === "Chase")
const goldManBank = bankData.filter(el => el.bank === "Goldman Sachs")
const wellsFargoBank = bankData.filter(el => el.bank === "Wells Fargo")

score 1 · Accepted Answer · answered Jan 16 '21 at 15:29

You could take an object for grouping.

const
    data = [{ bank: "Chase", monthEndBalance: "72,175.88", bankStatementDate: "2020/10/31" }, { bank: "Chase", monthEndBalance: "93,412.79", bankStatementDate: "2020/07/31" }, { bank: "Chase", monthEndBalance: "88,175.88", bankStatementDate: "2020/11/30" }, { bank: "Chase", monthEndBalance: "102,200.12", bankStatementDate: "2020/12/31" }, { bank: "Goldman Sachs", monthEndBalance: "72,276.12", bankStatementDate: "2020/11/30" }, { bank: "Goldman Sachs", monthEndBalance: "52,276.12", bankStatementDate: "2020/10/31" }, { bank: "Goldman Sachs", monthEndBalance: "102,276.12", bankStatementDate: "2020/12/31" }, { bank: "Wells Fargo", monthEndBalance: "33,276.12", bankStatementDate: "2020/11/30" }, { bank: "Wells Fargo", monthEndBalance: "12,276.12", bankStatementDate: "2020/10/31" }, { bank: "Wells Fargo", monthEndBalance: "150,276.12", bankStatementDate: "2020/12/31" }],
    result = data.reduce((r, o) => {
        (r[o.bank] ??= []).push(o);
        return r;
    }, {});

console.log(result);

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Filtering Array of Objects into multiple array of objects based on property

1 Answers1