Is searching for duplicate entries in an array using a specific key?

Question

Is searching for duplicate entries in an array using a specific key?

Below is an array structure:

[
  {
    "Date": "2020-07",
    "data": [
      {
        "id": "35ebd073-600c-4be4-a750-41c4be5ed24a",
        "Date": "2020-07-03T00:00:00.000Z",
        "transactionId": "13",
        "transactionType": "Payment",
        "amount": 1500
      }
    ]
  },
  {
    "Date": "2020-07",
    "data": [
      {
        "id": "4e126519-e27b-4e82-bb81-689c7dc63c9b",
        "Date": "2020-07-02T00:00:00.000Z",
        "transactionId": "4",
        "transactionType": "Payment",
        "amount": 1000
      }
    ]
  },
  {
    "Date": "2020-06",
    "data": [
      {
        "id": "646d6497-9dea-4f27-896e-a45d97a252ea",
        "Date": "2020-06-04T00:00:00.000Z",
        "transactionId": "14",
        "transactionType": "Payment",
        "amount": 1500
      }
    ]
  },
  {
    "Date": "2020-06",
    "data": [
      {
        "id": "cf44e27f-2111-462d-b3bd-420a193745b8",
        "Date": "2020-06-02T00:00:00.000Z",
        "transactionId": "5",
        "transactionType": "Payment",
        "amount": 1000
      }
    ]
  }
]

The key Date has multiple values for the same date. The goal is to merge data array records if the Dates are the same.

The expected output after merging is:

[
  {
    "Date": "2020-07",
    "data": [
      {
        "id": "35ebd073-600c-4be4-a750-41c4be5ed24a",
        "Date": "2020-07-03T00:00:00.000Z",
        "transactionId": "13",
        "transactionType": "Payment",
        "amount": 1500
      },
      {
        "id": "4e126519-e27b-4e82-bb81-689c7dc63c9b",
        "Date": "2020-07-02T00:00:00.000Z",
        "transactionId": "4",
        "transactionType": "Payment",
        "amount": 1000
      }
    ]
  },
  {
    "Date": "2020-06",
    "data": [
      {
        "id": "646d6497-9dea-4f27-896e-a45d97a252ea",
        "Date": "2020-06-04T00:00:00.000Z",
        "transactionId": "14",
        "transactionType": "Payment",
        "amount": 1500
      },
       {
        "id": "cf44e27f-2111-462d-b3bd-420a193745b8",
        "Date": "2020-06-02T00:00:00.000Z",
        "transactionId": "5",
        "transactionType": "Payment",
        "amount": 1000
      }
    ]
  }
]

What would be the most efficient way to achieve this?

javascript arrays json typescript lodash

Answer 1

Answer №1

If you want to efficiently manage data in JavaScript, consider using a dictionary. This allows you to easily check if a key already exists and append new data, or create a new entry if the key is not found.

var dict = {};
if (!("xxxx-xx" in dict)){ // Check if key does not exist

    dict["xxxx-xx"] = [{       // Store data as an array for future additions
         id: "....",
         transactionId: "..."
         // Add more properties here...
    }]
}

else {                           // If key already exists, push new data to the array
    dict["xxxx-xx"].push({       // Use push method to add object to existing array
         id: "....",
         transactionId: "..."
         // Add more properties here...
    })
}

Using a dictionary instead of an array can be more efficient for checking if a key already exists and to avoid duplicates with ease.

Answer 2

If you want to efficiently manage data in JavaScript, consider using a dictionary. This allows you to easily check if a key already exists and append new data, or create a new entry if the key is not found.

var dict = {};
if (!("xxxx-xx" in dict)){ // Check if key does not exist

    dict["xxxx-xx"] = [{       // Store data as an array for future additions
         id: "....",
         transactionId: "..."
         // Add more properties here...
    }]
}

else {                           // If key already exists, push new data to the array
    dict["xxxx-xx"].push({       // Use push method to add object to existing array
         id: "....",
         transactionId: "..."
         // Add more properties here...
    })
}

Using a dictionary instead of an array can be more efficient for checking if a key already exists and to avoid duplicates with ease.

Answer 3

Answer №2

arr = the dataset you provide

obj = the output generated from this process

arr.forEach((element) => {
    if(obj[element.Date]) {
       obj[element.Date].values.push(element.values);
    } else {
       obj[element.Date] = {
       values: [element.values]
    }
  }
});

Answer 4

arr = the dataset you provide

obj = the output generated from this process

arr.forEach((element) => {
    if(obj[element.Date]) {
       obj[element.Date].values.push(element.values);
    } else {
       obj[element.Date] = {
       values: [element.values]
    }
  }
});

Answer 5

Answer №3

To start, the array of objects needs to be grouped by the property Date. After that, iterate through the grouped data using key-value pairs of [Date, groupsByDate] and extract data from each group.

const result = _.chain(data)
  .groupBy("Date")
  .toPairs()
  .map(([key, value]) => ({
    Date: key,
    data: _.flatMap(value, "data"),
  }))
  .value()

Here is the complete code:

const data = [
  {
    Date: "2020-07",
    data: [
      {
        id: "35ebd073-600c-4be4-a750-41c4be5ed24a",
        Date: "2020-07-03T00:00:00.000Z",
        transactionId: "13",
        transactionType: "Payment",
        amount: 1500,
      },
    ],
  }
  // Additional object data here...
]

// Using lodash to group data by date and extract relevant information
const result = _.chain(data)
  .groupBy("Date")
  .toPairs()
  .map(([key, value]) => ({
    Date: key,
    data: _.flatMap(value, "data"),
  }))
  .value()

console.log(JSON.stringify(result, null, 2))

<script src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="0e62616a6f7d664e3a203f39203c3e">[email protected]</a>/lodash.min.js"></script>

Answer 6

To start, the array of objects needs to be grouped by the property Date. After that, iterate through the grouped data using key-value pairs of [Date, groupsByDate] and extract data from each group.

const result = _.chain(data)
  .groupBy("Date")
  .toPairs()
  .map(([key, value]) => ({
    Date: key,
    data: _.flatMap(value, "data"),
  }))
  .value()

Here is the complete code:

const data = [
  {
    Date: "2020-07",
    data: [
      {
        id: "35ebd073-600c-4be4-a750-41c4be5ed24a",
        Date: "2020-07-03T00:00:00.000Z",
        transactionId: "13",
        transactionType: "Payment",
        amount: 1500,
      },
    ],
  }
  // Additional object data here...
]

// Using lodash to group data by date and extract relevant information
const result = _.chain(data)
  .groupBy("Date")
  .toPairs()
  .map(([key, value]) => ({
    Date: key,
    data: _.flatMap(value, "data"),
  }))
  .value()

console.log(JSON.stringify(result, null, 2))

<script src="https://cdn.jsdelivr.net/npm/<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="0e62616a6f7d664e3a203f39203c3e">[email protected]</a>/lodash.min.js"></script>

Is searching for duplicate entries in an array using a specific key?

Answer №1

Answer №2

Answer №3

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