使用PHP处理复选框并使某些选项组合无效

Question

So this particular class assignment has us coding radio buttons and checkboxes in html but we use PHP to process the information. I have a very basic understanding of PHP so this exercise has so far given me trouble.

We have to program the checkboxes to their own array then pass the form data to the PHP script. We are supposed to not allow the selection of certain radio buttons with certain checkboxex and print warnings that those choices are invalid. For example the following statement:

radio1 is valid with all checkboxes but radio two is invalid with checkbox 3

I have seen a lot of examples of if(isset[]) statements nested with other if statements but I am still unable to get the desired outcome. The simplest solution is preferred.

Answer 1

The isset() keyword is used to check that a variable is set, that could still be set to value null.

Your best option is to check both isset() and !empty() so you know the value is not null also.

Heres an example:

<form method="post">
    <select name="param">
        <option value="value"> 1 </option>
   </select>
 </form>

You can now use the super variable $_POST to access this information on submission which is an array data type. The index points are the names of what you put, in this case I called my select box param.

echo (isset($_GET['param']) && !empty($_GET['param'])) ? $_GET['param'] : 'Please fill in the required select box..';