Keep the final item in an array that shares the same attribute

Question

Keep the final item in an array that shares the same attribute

I am working with an array

const obj=[{fullCart: 5, halfCart: 4, smu: 3, stowage: 5, index: "FC-093"},
 {fullCart: 5, halfCart: 4, smu: 8, stowage: 5, index: "FC-093"},
 {fullCart: 5, halfCart: 4, smu: 0, stowage: 5, index: "FC-093"},
 {fullCart: 5, halfCart: 5, smu: 3, stowage: 5, index: "FC-093"},
 {fullCart: 5, halfCart: 7, smu: 3, stowage: 5, index: "FC-093"/}
 ]

In my code, I need to keep the last object in the array which has the same property 'index' as the previous one. In this case, objects with index 'FC-093' should be removed, resulting in:

[{fullCart: 5, halfCart: 7, smu: 3, stowage: 5, index: "FC-093/"}]

javascript arrays

Answer 1

Answer №1

Here is the solution you've been looking for.

To extract every unique index value from an array, utilize the .map() method
Iterate through the unique array and employ the findLast method to retrieve the last element in the object array based on each value in the unique array, then add it to the result array

const obj=[
 {fullCart: 5, halfCart: 4, smu: 3, stowage: 5, index: "FC-093"},
 {fullCart: 5, halfCart: 4, smu: 8, stowage: 5, index: "FC-093"},
 {fullCart: 5, halfCart: 4, smu: 0, stowage: 5, index: "FC-093"},
 {fullCart: 5, halfCart: 5, smu: 3, stowage: 5, index: "FC-093"},
 {fullCart: 10, halfCart: 7, smu: 3, stowage: 5, index: "FC-093"},
 {fullCart: 3, halfCart: 6, smu: 4, stowage: 5, index: "FC-095"},
 {fullCart: 3, halfCart: 6, smu: 5, stowage: 5, index: "FC-095"},
 {fullCart: 10, halfCart: 7, smu: 8, stowage: 5, index: "FC-095"},
 {fullCart: 2, halfCart: 8, smu: 10, stowage: 5, index: "FC-098"},
 {fullCart: 10, halfCart: 9, smu: 2, stowage: 5, index: "FC-098"}
];
let result = [];//initialize result array

//generate a unique array
const unique = [...new Set(obj.map(item => item.index))];
console.log(unique)//prints every unique value from key index found in an array 

//iterate through unique array
unique.forEach(ele => {
  //retrieve the last element with matching index value in the unique array
  let res = obj.findLast((element) => element.index == ele);
  result.push(res)
})

console.log(result)//expected output

Answer 2

Here is the solution you've been looking for.

To extract every unique index value from an array, utilize the .map() method
Iterate through the unique array and employ the findLast method to retrieve the last element in the object array based on each value in the unique array, then add it to the result array

const obj=[
 {fullCart: 5, halfCart: 4, smu: 3, stowage: 5, index: "FC-093"},
 {fullCart: 5, halfCart: 4, smu: 8, stowage: 5, index: "FC-093"},
 {fullCart: 5, halfCart: 4, smu: 0, stowage: 5, index: "FC-093"},
 {fullCart: 5, halfCart: 5, smu: 3, stowage: 5, index: "FC-093"},
 {fullCart: 10, halfCart: 7, smu: 3, stowage: 5, index: "FC-093"},
 {fullCart: 3, halfCart: 6, smu: 4, stowage: 5, index: "FC-095"},
 {fullCart: 3, halfCart: 6, smu: 5, stowage: 5, index: "FC-095"},
 {fullCart: 10, halfCart: 7, smu: 8, stowage: 5, index: "FC-095"},
 {fullCart: 2, halfCart: 8, smu: 10, stowage: 5, index: "FC-098"},
 {fullCart: 10, halfCart: 9, smu: 2, stowage: 5, index: "FC-098"}
];
let result = [];//initialize result array

//generate a unique array
const unique = [...new Set(obj.map(item => item.index))];
console.log(unique)//prints every unique value from key index found in an array 

//iterate through unique array
unique.forEach(ele => {
  //retrieve the last element with matching index value in the unique array
  let res = obj.findLast((element) => element.index == ele);
  result.push(res)
})

console.log(result)//expected output

Answer 3

Answer №2

Using this code snippet, you can iterate through all elements and retain only the last element with a specific id.

let finalResult = Object.values(objects.reduce((accumulator, element) => {
  accumulator[element.identifier] = element;
  return accumulator;
}, {}));

Answer 4

Using this code snippet, you can iterate through all elements and retain only the last element with a specific id.

let finalResult = Object.values(objects.reduce((accumulator, element) => {
  accumulator[element.identifier] = element;
  return accumulator;
}, {}));

Answer 5

Answer №3

It seems like there might be some confusion regarding your query. If you're looking to retrieve the last element, you can achieve that with the following code snippet:


    function getLastElement(arr) {
        let lastIndex = arr.length - 1;
        return arr[lastIndex];
    }

Alternatively, if you want to eliminate the last element from the array, you can create a new array and assign it to the existing one like this:


let originalArray = [0, 1, 2, 3, 4, 5]

function createNewArray(arr) {
    return arr.slice(0, -1);
}

originalArray = createNewArray(originalArray);
// originalArray now holds [0, 1, 2, 3, 4]

Answer 6

It seems like there might be some confusion regarding your query. If you're looking to retrieve the last element, you can achieve that with the following code snippet:


    function getLastElement(arr) {
        let lastIndex = arr.length - 1;
        return arr[lastIndex];
    }

Alternatively, if you want to eliminate the last element from the array, you can create a new array and assign it to the existing one like this:


let originalArray = [0, 1, 2, 3, 4, 5]

function createNewArray(arr) {
    return arr.slice(0, -1);
}

originalArray = createNewArray(originalArray);
// originalArray now holds [0, 1, 2, 3, 4]

Keep the final item in an array that shares the same attribute

Answer №1

Answer №2

Answer №3

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