Append characters to the end of a string

function appendString(length, StringToAppendTo, appendStringWith) {

  var returnString = ""

  returnString += StringToAppendTo;

  if (StringToAppendTo.length < length) {

    for (var i = 0; i < length - 1; i++) {

      returnString += appendStringWith;

    }

  }

  return returnString;

}

Use it like this:

var appendedString = appendString(2, "1", "0");