JSFiddle - React, Tailwind, and code Playground

by dance2die

JavaScript

const arr = [1, 1, 2, 2, 2, 3, 3, 3, 3];
var uniqueInOrder = function(iterable) {
  return [].filter.call(iterable, function(a, i) {
    return iterable[i - 1] !== a;
  });
};

console.log(uniqueInOrder(arr));