禁用选择下拉检查PHP

Question

I have a couple of drop down boxes I access through POST with PHP. When the boxes are disabled and not equal to zero I have the program do something. However when they are disabled I do not want them to do anything. The way I check if the boxes are active is by using an if statement

if ($_POST['box'] != "blank"){

//do something

}

So basically I check if the box is not in the default blank position run the if statement.

However when it is disabled I am not sure how to check or what kind of value it returns if any. What can I add to the if statement so it will not go into the loop when the boxes are disabled?

I tried:

   if ($_POST['box'] != "blank" || $_POST['box'] != ""){

    //do something

    }

But that did not work. Any ideas?

Answer 1

It is important to understand that a form is just something that sends an HTTP POST request to a web server. From PHP's point of view, it has no idea that someone clicked submit on a form, it just sees some POST data that could have came from anywhere.

That said, a disabled form element will not be submitted. Instead, try something like

if (!isset($_POST['box'])) {
    //box was not submitted
}