javascript - How to concatenate/change the error message if the input is not a valid date in js? -

i tried 2 days still nothing. maybe can highly skilled in javascript loops.

i asked question before , change code still no luck in showing expected data. , still struggling this.

i have code:

$(function(){ var len = $('#groupcontainer > div').length; var data = []; for(var i=0; < len; i++){      var number = $('#number_' + [i + 1]);     var date = $('#date_' + [i + 1]);     var count = + 1;     var message ="";     var = number.map(function(){         return this.value;     });     var b = date.map(function(){         return this.value;     });      var newobj = {number: a[0], date: b[0]}     data.push(newobj); }  var message = ""; for(var c = 0; c < data.length; c++) {             haveerroringroup = false;     for(var d in data[c])     {         if(data[c].hasownproperty(d))         {                   if(data[c][d] == "")             {                 if(!haveerroringroup){                     haveerroringroup= true;                    message += 'group: ' + [c + 1] + '\n';                 }                  message +=  d + ' required!\n';             }             if(d == "date")             {                 if(data[c][d].length != 22 && data[c][d] != "")                 {                     message += 'invalid date!\n';                 }              }          }      }   } if(message){     alert(message); }  }); 

and expected output:

if fields in group 1 filled , group 2 not show alertbox:

   group 2:    number required!    date required! 

if field not filled show:

   group 1, 2 number required!    group 1, 2 date required! 

and if date not date:

  group 1, 2 date invalid. 

and if 1 of inputs invalid.

  group 2 date invalid. 

if field filled nothing.

here's fiddle

i think looking jquery-validate. i'm pretty sure comes native date validator if want have more specific format can put regex it.