In the scenario where there are duplicate 'id' keys within the array of objects, what is the best method to remove the object with the duplicate key?

Question

In the scenario where there are duplicate 'id' keys within the array of objects, what is the best method to remove the object with the duplicate key?

When there are duplicate 'id' keys among the objects in the array, how can you remove the object with the duplicated 'id'?

I attempted to use filter, map, and set methods, but none of them were successful. Since the array is not one-dimensional, I am unsure of the correct approach.

Original:

"category": {
    "key": 1,
    "order": 1,
    "list": [
        {
            "id": "12345",
            ...
        },
        {
            "id": "12345",
            ...
        },
        {
            "id": "67890",
            ...
        },
        
    ]
}

Desired Output:

"category": {
    "key": 1,
    "order": 1,
    "list": [
        {
            "id": "12345",
            ...
        },
        {
            "id": "67890",
            ...
        },
        
    ]
}

javascript dictionary filter duplicates

Answer 1

Answer №1

By utilizing the reduce function on the list, we are able to iterate over each item and determine if the accessed key has been visited using the keys parameter within the reduce method. If the key has not been visited, the object is added to a filtered array and the keys array is returned to ensure it remains updated.

const data = {
  "category": {
    "key": 1,
    "order": 1,
    "list": [{
        "id": "12345"
      },
      {
        "id": "12345"
      },
      {
        "id": "67890"
      },

    ]
  }
}
let filtered = [];

data.category.list.reduce((keys, currentObject) => {
  if (!keys.includes(currentObject.id)) { //checking if current oject id is present in keys or not
    // if not present than we will just push that object in 
    keys.push(currentObject.id);
    //getting filttered object
    filtered.push(currentObject);
  }
  return keys; //returning keys to update it
}, [])
data.category.list = filtered; //updating list
console.log(data);

Answer 2

By utilizing the reduce function on the list, we are able to iterate over each item and determine if the accessed key has been visited using the keys parameter within the reduce method. If the key has not been visited, the object is added to a filtered array and the keys array is returned to ensure it remains updated.

const data = {
  "category": {
    "key": 1,
    "order": 1,
    "list": [{
        "id": "12345"
      },
      {
        "id": "12345"
      },
      {
        "id": "67890"
      },

    ]
  }
}
let filtered = [];

data.category.list.reduce((keys, currentObject) => {
  if (!keys.includes(currentObject.id)) { //checking if current oject id is present in keys or not
    // if not present than we will just push that object in 
    keys.push(currentObject.id);
    //getting filttered object
    filtered.push(currentObject);
  }
  return keys; //returning keys to update it
}, [])
data.category.list = filtered; //updating list
console.log(data);

Answer 3

Answer №2

Based on a helpful suggestion from @Nick

let myData ={
"category": {
    "key": 1,
    "order": 1,
    "list": [
        {
            "id": "12345"
        },
        {
            "id": "12345"
        },
        {
            "id": "67890"
        },
        
    ]
}
}


let uniqueData = myData.category.list.filter((obj,index,arr) => arr.findIndex(obj2 => obj2.id == obj.id) == index)
myData.category.list = uniqueData
console.log(myData)

Answer 4

Based on a helpful suggestion from @Nick

let myData ={
"category": {
    "key": 1,
    "order": 1,
    "list": [
        {
            "id": "12345"
        },
        {
            "id": "12345"
        },
        {
            "id": "67890"
        },
        
    ]
}
}


let uniqueData = myData.category.list.filter((obj,index,arr) => arr.findIndex(obj2 => obj2.id == obj.id) == index)
myData.category.list = uniqueData
console.log(myData)

Answer 5

Answer №3

To efficiently track unique ids, you can utilize a set in JavaScript:

const category = [{
  "category": {
    "key": 1,
    "order": 1,
    "list": [{
        "id": "12345",
      },
      {
        "id": "12345",
      },
      {
        "id": "67890",
      },

    ]
  }
}]
const z = category.map(elem => {
  const set = new Set()
  return {
    ...elem,
    category: {
      ...elem.category,
      list: elem.category.list.reduce((acc, curr) => {
        if (!set.has(curr.id)) {
          set.add(curr.id);
          acc.push(curr)
        }
        return acc;
      }, [])
    }
  }
});
console.log(z)

Answer 6

To efficiently track unique ids, you can utilize a set in JavaScript:

const category = [{
  "category": {
    "key": 1,
    "order": 1,
    "list": [{
        "id": "12345",
      },
      {
        "id": "12345",
      },
      {
        "id": "67890",
      },

    ]
  }
}]
const z = category.map(elem => {
  const set = new Set()
  return {
    ...elem,
    category: {
      ...elem.category,
      list: elem.category.list.reduce((acc, curr) => {
        if (!set.has(curr.id)) {
          set.add(curr.id);
          acc.push(curr)
        }
        return acc;
      }, [])
    }
  }
});
console.log(z)

In the scenario where there are duplicate 'id' keys within the array of objects, what is the best method to remove the object with the duplicate key?

Answer №1

Answer №2

Answer №3

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