Why is this JSON variable undefined? [closed]

Question

I've got the following code.

JavaScript

<script>
function postUser() {
    var user = $('span input').serialize;
    alert(user.username);
}
</script>

HTML

<span>
  User name : <input type="text" name="username"><br />
  Password: <input type="password" name="password" /><br />
  First name: <input type="text" name="firstName" /><br />
  Last name: <input type="text" name="lastName" /><br />

  <button onclick="postUser()">Submit</button>
</span>

When I populate the items in the UI, the alert says "undefined" - but I thought by serializing the array it should be a JSON object? Any ideas why username is undefined?

Answer 1

You forgot the () in order to call the function.

var user = $('span input').serialize();

---

Furthermore, .serialize() gives you a string result, not an object.

Perhaps you wanted this instead:

var username = $('span input[name=username]').val();

---

If you want an object that references all the values, you'll need to make it.

var vals = {};

$('span input').each(function() {
    vals[this.name] = this.value;
});

var name = vals.username;

Answer 2

You don't need serialize here.

What you need is to get the value of the input whose name is "username" :

alert($('input[name="username"]').val());