How does jQuery Validation setups the validation message?

Question

I wrote an additional method for jquery validation plugin that checks if a given value meets the length requirements defined along with the validation process.

So the method looks like this:

jQuery.validator.addMethod("exactLength", function(value, element, param){
    var len = value.length;
    if ($.isArray(param)){
        if (param.indexOf(len) !== -1){
            return true;
        } else {
            return false;
        }
    } else {
        if (param != len){
            return false;
        } else {
            return true;
        }
    }

}, jQuery.format("Value must have {0} characters"));

It works but the only problem is that message sent to the user doesn't meet my needs. The reason why is because one field might have more than 1 valid length.

A bank code can have 8 or 11 digits. So, if I define the options below I expect the following output in case of error: "Please, the value must have 8 or 11 digits."

{
"options":{
  "rules":  {
     "inputx": {
        "required":     true,
        "exactLength":  [8,11]
      }
   }
}
}

But I want more flexibility because i can have 2 values defined as valid lengths, "Please, the value must have 8, 11, xxx or 23 digits" Or i can basic field where the input must have only 1 specific length "please, the value must have 8 digits"

So, inside the method is it possible to tell want should be passed to the message?

EDIT:

Added full solution based on Arun P Johny answer

jQuery.validator.addMethod("exactLength", function(value, element, param){
    var len = value.length;
    if ($.isArray(param)){
        if (param.indexOf(len) !== -1){
            return true;
        } else {
            return false;
        }
    } else {
        if (param != len){
            return false;
        } else {
            return true;
        }
    }

}, function(param, element){
    var str = "";

    if ($.isArray(param)){
        var paramLen = param.length,
                lastParamValue = param[ paramLen - 1];

        if (paramLen == 2){
            str = param[0];
        } else {
            for(var i = 0; i< paramLen - 1; i++){

                if (i == paramLen - 1){
                    str += ',' + param[i];
                }   else {
                    if (i == 0)
                        str += param[0];
                    else
                        str += ',' + param[i];
                }
            }
        }

        return jQuery.format("Value must have {0} or {1} characters", str, lastParamValue );

    } else {
        return jQuery.format("Value must have {0} characters", param )
    }


});

Answer 1

The message option can be a function so

jQuery.validator.addMethod("exactLength", function (value, element, param) {
    var len = value.length;
    if ($.isArray(param)) {
        if (param.indexOf(len) !== -1) {
            return true;
        } else {
            return false;
        }
    } else {
        if (param != len) {
            return false;
        } else {
            return true;
        }
    }
}, function (param, element) {
    //you can customize the string generation here, params refers to the array passed to the rule
    return "Value must have " + param.join(',') + " characters"
});

Demo: Fiddle