counting number of empty inputs with a certain class

Question

I have tried a couple of solutions from previous questions, but no luck. Hoping someone can help me out.

I have a section of a form where fields are dynamically crea

Answer 1

This will give you all empty inputs:

$('.user_field').filter(function(){
    return !$(this).val();
}).length;

Answer 2

$('.user_field').blur(function(){
    alert ($('.user_field').filter('[value=""]').length);
});

DEMO

Answer 3

mm just posting my version using .not

$('.user_field').blur(function() {
   var count = $('.user_field').not(function() {
        return this.value;
    }).length;

    alert(count);
});

DEMO