JavaScript function to split, sort, and filter out repeats from a string

index.html

<p id="comma-output"></p>
<p id="space-output"></p>

SplitSortFilterStr.js

// Function to sort words then strip out repeats
// Used to get unique keywords from different web languages/tools I've used to get ideas for blog posts. I tend to have a lot of repeats...

const commaSeparated = "split, sort, and, filter, strings, separated, by, commas, with, no, repeats, repeats, repeats";
const spaceSeparated = "split sort and filter strings separated by spaces with no repeats repeats repeats";

let commaWords = [];
let spaceWords = [];

function splitStrings(str, separator, output) {
  return str
    .toLowerCase()
    .split(separator)
    .sort((a, b) => a.localeCompare(b))
    .filter(word => {
      if (!output.includes(word)) {
        output.push(word);
      }
    });
}
const commaCount = splitStrings(commaSeparated, ", ", commaWords);
document.getElementById("comma-output").innerHTML = commaWords.join(", ");

splitStrings(spaceSeparated, " ", spaceWords);
document.getElementById("space-output").innerHTML = spaceWords.join(", ");