Remove duplicates from array and remove the same index from another array-CodePudding

I have 2 arrays, one array contains prices and the other one dates. I want to remove all duplicate prices , and I want to remove the same indexes of the date array. How would one do this?

An example of my arrays:

['2022-06-27', '2022-07-02', '2022-07-03', '2022-07-04', '2022-07-05']
 [3.79, 4.29, 4.29, 4.29, 4.36]

end result needed:

 ['2022-06-27', '2022-07-02', '2022-07-05']
 [3.79, 4.29, 4.36]

CodePudding user response：

A for loop, splicing along the way all the duplicates found using arr.lastIndexOf(item).

var arr2 = ['2022-06-27', '2022-07-02', '2022-07-03', '2022-07-04', '2022-07-05'];
var arr1 = [3.79, 4.29, 4.29, 4.29, 4.36];

for (var i = 0; i < arr1.length; i  ) {
  var current = arr1[i];
  var lastIndex = arr1.lastIndexOf(current);
  while (lastIndex > i) {
    arr1.splice(lastIndex, 1);
    arr2.splice(lastIndex, 1);
    lastIndex = arr1.lastIndexOf(current);
  }
}
console.log(arr1)
console.log(arr2)

CodePudding user response：

You can try this approach:

const dates = ['2022-06-27', '2022-07-02', '2022-07-03', '2022-07-04', '2022-07-05'] 
const arr = [3.79, 4.29, 4.29, 4.29, 4.36];

const arrSet = new Set(arr);
const relatedDates = [...arrSet].map((value) => dates[arr.indexOf(value)]);

console.log([...arrSet]);
console.log(relatedDates);

Output:

[3.79, 4.29, 4.36]
['2022-06-27', '2022-07-02', '2022-07-05']

CodePudding user response：

You could take the values of a hash table with prices as keys as filtered indices. Then map dates and prices as result.

const
    dates = ['2022-06-27', '2022-07-02', '2022-07-03', '2022-07-04', '2022-07-05'],
    prices = [3.79, 4.29, 4.29, 4.29, 4.36],
    indices = Object.values(prices.reduce((r, p, i) => (r[p] ??= i, r), {})),
    datesNew = indices.map(i => dates[i]),
    pricesNew = indices.map(i => prices[i]);

console.log(...datesNew);
console.log(...pricesNew);