Serialize is not correct

Form elements must be submitable. There must be a `name` attribute, otherwise it will submit some useless character.
```html
<form>
    <input type="text" name="foo" value="bar">
    <input type="text">
    <input type="text">
    <input type="text">
</form>
```
This is not correct
```js
$('form').serialize();
// foo=bar&=&=&=
```

The determination method of `jQuery`, (serializeArray)
```js
this.name && !jQuery( this ).is( ":disabled" ) &&
rsubmittable.test( this.nodeName ) && !rsubmitterTypes.test( type ) &&
( this.checked || !rcheckableType.test( type ) )
```