JS for a friend's SquareSpace page to clean up titles beginning with "Category//"

cleanTitles.js

window.onload = function() {
  cleanTitles();
  function cleanTitles() {
    var arr = document.getElementsByClassName("index-item-title-text");
    for (var i = 0; i < arr.length; i++) {
      var element = arr[i];
      element.innerText = stripCategory(element.innerText);
    }
  }
  function stripCategory(str) {
    var index = str.indexOf("//");
    if (index !== -1) {
      index = index + 2;
      str = str.slice(index, str.length);
    }
    return str;
  }
}