Replace special characters

replaceSpecialChars.js

var specialChars = [
  {val:"a",let:"áàãâä"},
  {val:"e",let:"éèêë"},
  {val:"i",let:"íìîï"},
  {val:"o",let:"óòõôö"},
  {val:"u",let:"úùûü"},
  {val:"c",let:"ç"},
  {val:"A",let:"ÁÀÃÂÄ"},
  {val:"E",let:"ÉÈÊË"},
  {val:"I",let:"ÍÌÎÏ"},
  {val:"O",let:"ÓÒÕÔÖ"},
  {val:"U",let:"ÚÙÛÜ"},
  {val:"C",let:"Ç"},
  {val:"",let:"?!()"}
];

function replaceSpecialChars(string) {
  var $spaceSymbol = '-';
  var regex;
  var result = string;
  for (var i = 0; i < specialChars.length; i++) {
    regex = new RegExp("["+specialChars[i].let+"]", "g");
    result = returnString.replace(regex, specialChars[i].val);
    regex = null;
  }
  return result.replace(/\s/g,$spaceSymbol);
};