How to validate in jQuery only if all fields are blank

Using jQuery validation, if I have many fields on a page, and only require ONE of them to be filled, how do I raise an error only if they are all bla开发者_JAVA技巧nk.

That is, the user can fill one or more fields, but if all of them are blank, there will be an error. I want to know if there is a way of doing this with jQuery validation.

Something along these lines should work.

var valid=0;
$("#myform input[type=text]").each(function(){
  if($(this).val() != "") valid+=1;
});

if(valid){
  console.log(valid + " inputs have been filled");
}
else {
  console.log("error: you must fill in at least one field");
}

See a working example here on jsFiddle

var filled = $("#theForm :input").filter(function() {
    return $.trim(this.value).length;
});
if(filled.length) {
    // at least one has been filled
} else {
    // error, all are blank
}

You can test it here.

Reference:

• http://api.jquery.com/input-selector/
• http://api.jquery.com/filter/

try this ,

    var name = $('#name').val();
    var city = $('#city').val();

    if(name == '' && city == '') // this will only fire when both name and city are empty if one of them is not empty than this if condition will not fire
    {
       alert('all fields are required');
    }