index.js
function stringEscape (str) {

  let stringArray = str.toString().split('');

  for (let j = 0; j < stringArray.length; j++) {
    for (let i = 0; i < escapeArray.length; i++) {

      if (stringArray[j] === escapeArray[i]) {
        stringArray[j] = '\\' + escapeArray[i];
      }

    }
  }

  return stringArray.join('');
}
function stringEscape (str) {

  let stringArray = str.toString().split('');

  for (let j = 0; j < stringArray.length; j++) {
    for (let i = 0; i < escapeArray.length; i++) {

      if (stringArray[j] === escapeArray[i]) {
        stringArray[j] = '\\' + escapeArray[i];
      }

    }
  }

  return stringArray.join('');
}
The string that needs to be matched is escaped