function toTitleCase(str) {
  //store the first letter in firstChar
  let firstChar = str[0] || "";
  //capitalize firstChar
  firstChar = firstChar.toUpperCase();
  //store the remaining characters in a variable otherChars
  let otherChars = "";
  if (str.length > 1) otherChars = str.substring(1, str.length);
  return `${firstChar}${otherChars}`;
  //return a concatenation of firstChar and otherChars
}