I need to find the total number of occurrences of a particular item in JSON Response using postman tool

Question

[
    {
        "branchCode": "111",
        "referenceNumber": "2222",
        "comments": "Write Off",
        "transactionDate": "2022-02-23T00:00:00",
        "amount": 0,
        "accountCode": "MMMM",
        "accountName": "Metal MMMM",
        "allocations": [
            {
                "branchCode": "111",
                "referenceNumber": "3333",
                "allocationDate": "2022-02-23T09:23:57",
                "ledgerTypeDescription": "Client",
                "accountCode": "MMMM",
                "accountName": "Metal MMMM",
                "amount": -0.02
            }
        ]
    },
    {
        "branchCode": "222",
        "referenceNumber": "33333",
        "comments": "To write off historic med fee $0",
        "transactionDate": "2022-03-24T00:00:00",
        "amount": 0,
        "accountCode": "OOOO",
        "accountName": "Oranga OOOO - AEP",
        "allocations": [
            {
                "branchCode": "222",
                "referenceNumber": "456",
                "allocationDate": "2022-03-24T10:39:02",
                "ledgerTypeDescription": "Client",
                "accountCode": "OOOOP",
                "accountName": "Oranga 0000 - AEP",
                "amount": 94.88
            }
        ]
    }
]

In the above JSON Response i need to find how many Allocations have been done in the entire Response. Can i do this using a for loop , If so how to use it to iterate through the Array and then count the Allocations item

I tried using the Object.keys(jsondata[0]).length) method. But this is useful to find the length of the items in a specific block. But i could not understand how to traverse through an array and find the number of allocations

Answer 1

Another option is to use flatMap() to get all the allocations on which you can call .length:

const data = [{"branchCode": "111", "referenceNumber": "2222", "comments": "Write Off", "transactionDate": "2022-02-23T00:00:00", "amount": 0, "accountCode": "MMMM", "accountName": "Metal MMMM", "allocations": [{"branchCode": "111", "referenceNumber": "3333", "allocationDate": "2022-02-23T09:23:57", "ledgerTypeDescription": "Client", "accountCode": "MMMM", "accountName": "Metal MMMM", "amount": -0.02 } ] }, {"branchCode": "222", "referenceNumber": "33333", "comments": "To write off historic med fee $0", "transactionDate": "2022-03-24T00:00:00", "amount": 0, "accountCode": "OOOO", "accountName": "Oranga OOOO - AEP", "allocations": [{"branchCode": "222", "referenceNumber": "456", "allocationDate": "2022-03-24T10:39:02", "ledgerTypeDescription": "Client", "accountCode": "OOOOP", "accountName": "Oranga 0000 - AEP", "amount": 94.88 } ] } ];

const n = data.flatMap(o => o.allocations).length;

console.log(n);