JS表单验证优化

var validate = (function(){
  var messages = {
      isEmail : '输入正确格式邮箱',
      isPhoneNum : '输入正确手机号'
  };

  var validateTypes ={
      isEmail:function(value){
        var reg = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
        if(!reg.test(value)){
            return true;
        }
        return false;
      },
      isPhoneNum:function(value){
          var reg = /^1[34578]\d{9}$/;
          if(!reg.test(value)){
              return true;
          }
          return false;
      }
  };
  return function(value,type){
      if(validateTypes[type](value)){
          return messages[type];
      }
  }
})();

console.log(validate("","isEmail")); //输入正确格式邮箱
console.log(validate("bilibiligo@gmail.com","isEmail")); //undefine
console.log(validate("test","isPhoneNum")); //手机号
console.log(validate("18824156554","isPhoneNum")); //undefine