Removing identical entries from an array keeping its length same - JavaScript

We have to write a function that takes in an array, removes all duplicates from it and inserts the same number of empty strings at the end.

For example −

If we find four duplicate values, we have to remove then all and insert four empty strings at the end.

Example

Following is the code −

const arr = [1,2,3,1,2,3,2,2,3,4,5,5,12,1,23,4,1]; const deleteAndInsert = arr => {    const creds = arr.reduce((acc, val, ind, array) => {       let { count, res } = acc;       if(array.lastIndexOf(val) === ind){          res.push(val);       }else{          count++;       };       return {res, count};    }, {       count: 0,       res: []    });    const { res, count } = creds;    return res.concat(" ".repeat(count).split(" ")); }; console.log(deleteAndInsert(arr));

Output

This will produce the following output in console −

[    2,  3,  5,  12, 23, 4,  1,    '', '', '', '', '', '', '',    '', '', '', '' ]