JSFiddle - React, Tailwind, and code Playground

by nerdess

JavaScript

function deleteNth(arr,n) {

var arrCopy = arr.slice();
var arrUnique = arrCopy.sort().filter(function(item, pos, arrTemp){
    return !pos || item != arrTemp[pos - 1];
  });
var arrDeleteIndexes = [];
  
for (i = 0; i < arrUnique.length; i++) {
  var counter = 0;
  for (j = 0; j < arr.length; j++) {

    if (arrUnique[i] === arr[j]) {
      counter++;
      if (counter > n) {
      	arrDeleteIndexes.push(j);
    	}
    }
  }
}

console.log(arrDeleteIndexes);
//arrDeleteIndexes.reverse();

for (i = arr.length; i >= 0; i--) {
  if (arrDeleteIndexes.includes(i)) {
    arr.splice(i,1);
  }
}

  
return arr;
  

}

deleteNth([20,37,20,21], 1);