Generate regex for accented characters example

example.js

var userInput='bla';
var regex = "";
var lookup = {
  "a": "à"
}
var accentedCharacters = "àèìòùÀÈÌÒÙáéíóúýÁÉÍÓÚÝâêîôûÂÊÎÔÛãñõÃÑÕäëïöüÿÄËÏÖÜŸçÇßØøÅåÆæœ";

function replaceLetterWithOrBlock(letter){
  var orBlock = letter;
  var accentedLetter = lookup[letter];
  if(accentedLetter){
    orBlock = "("+letter+"|"+accentedLetter+")";
  }

  return orBlock;
}

for ( var i = 0; i < userInput.length; i++ ) {
  regex += replaceLetterWithOrBlock(userInput.charAt(i))
}

console.log(regex)