Replace duplicates items in array with different values

Question

i would like to Replace duplicates items with different values.

eg arr = [1,1,1,1,2,2,2,3] i want to replace the duplicates with R

So the result looks like this arr = [1,R,R,R,2,R,R,3]

right now I'm using this approach:

    arr = [1,1,1,1,2,2,2,3]
    let previous = 0;
    let current = 1;
    while (current < arr.length) {
        if (arr[previous] === arr[current]) {
            arr[current] = 'R';
            current += 1;
        } else if (arr[previous] !== arr[current]) {
            previous = current;
            current += 1;
        }
    }

i wondering if there is different approach for to achieve that. for Example using Lodash (uniqwith, uniq).

Thanks

Answer 1

here's how I'd do it It look if the current element is the first of the array with the current value and replace it if not

It may take some times on very big arrays

const input = [1,1,1,1,2,2,2,3]
let output = input.map(
  (el, i) => input.indexOf(el) === i ? el : 'R'
)
console.log(output)