jquery 正则校验重复字符

//校验重复
function checkRepeated(str) {
      var reg = /(\w)[^\1]{0,}\1/g;
      return reg.test(str);
}
var flag = checkRepeated(course);
if (flag) {
  $.modal.alertError("字符串："+course+"<br/>是否有重复："+flag);
  return false;
}

//校验重复信息
//var str = "40,42,45,46,42,43,41,40";
function checkRepeated(str) {
  str = str.substring(0,str.lastIndexOf(","));
  var strs = str.split(",");
  var length = strs.length;
  for (var i = 0; i < length-1; i++) {
    for (var j = i+1; j < length; j++) {
      if (strs[i] == strs[j]) {
        return true;
      }
    }
  }
  return false;
}