PHP Form Empty Fields
Why
When form fields are empty, some data is not sent to the server. Sometimes the field is sent as an empty string; sometimes no field name is sent at all.
Action for empty fields
The following table illustrates the behavior of various form controls when they're not filled in or selected:
| Form Control | What Happens When It's Not Filled In Or Selected |
|---|---|
| Text input field | The field name is sent, along with an empty value. |
| Text area field | The field name is sent, along with an empty value. |
| Password field | The field name is sent, along with an empty value. |
| File select field | The field name is sent, along with an empty value. |
| Hidden field | The field name is sent, along with an empty value. |
| Checkbox field | Nothing is sent. |
| Radio button field | Nothing is sent. |
| Pull - down menu | A value is always sent. |
| List box | Nothing is sent. |
| Multi - select box | Nothing is sent. |
| Submit button | Nothing is sent if the button isn't clicked. |
| Image field | Nothing is sent if the button isn't clicked. |
| Reset button | Nothing is sent. |
| Push button | Nothing is sent. |