jQuery函数仅在文本框更改时运行

Question

I have a form that I need to do some validation on, my jquery seems to be working except when a user just enters the page and submits without making any entry into a text box. Here is my HTML:

...
<% while (rs.next()) { %>
<input type="text" name="name" />
<%  }  %>
<input type="text" id="fafsaNbrFam" name="fafsaNbrFam" value="<%=nbrFam%>" class="hidden" />
....

and my script:

 $("#submit").click(function(e) {
        var numEntries = 0;
        var fafsaNbr = 0;

        $("input[name^='name_']").each(function() {
          if (this.value) {
            numEntries++;
          }
        });

        fafsaNbr = parseInt($("input[name='fafsaNbrFam']").val());


        if (fafsaNbr > numEntries && !confirm("WARNING, numbers don't match.")) {
          e.preventDefault();
        }
      });

So basically if their number of text boxes filled with names isn't >= the hidden input value then the kick back happens, and it works except when the user never enters anything into the text box. What event could I use instead of $("input[name^='name_']").each(function() { to accomplish this?

Answer 1

According to me it wont work because when textbox is empty then

$("input[name^='name_']").each(function()

parseInt($("input[name='fafsaNbrFam']").val());

.each() and val() return null. Due to this your control did not run ahead.

One thing you can do:

document.getElementById("fafsaNbrFam")==null

using this you can check the value as true or false. Because in case of empty textbox when you write the document.getElementById("fafsaNbrFam") or $("#fafsaNbrFam") it return value null.

And, null.val() or null.each() gives error.