Question

I’m having a real problem with retrieving the value of a radio button using PHP . . . I have two radio buttons as such:

<input name="admin" type="radio" value="1" />Yes
<input name="admin" type="radio" value="0" checked />No

And a conditional PHP statement checking to see if PHP can retrieve any data from it:

if(!empty($_POST['admin'])) {
    // do stuff
}
else {
   echo "Value not set";
}

the problem is that PHP can seem to return a value for the radio buttons if “yes” is selected, but not if “no” is selected, I’ve tried removing the “checked” portion, to no avail. I just can’t get it to retrieve the “0” value whatever I try.

I remember using PHP arrays to name checkboxes, but this shouldn’t be needed for radio buttons surely, as only can be selected at any one time?

Or does PHP just have a problem returning radio buttons with a value of 0?

Or am I doing something horribly wrong without realising it?

Answer 1

PHP function empty will return false for 0, NULL, "", and others.

Quoting from php.net:

"" (an empty string)

0 (0 as an integer)

0.0 (0 as a float)

"0" (0 as a string)

NULL

FALSE

array() (an empty array)

var $var; (a variable declared, but without a value in a class)

All of these will return (false) therefore nullifying the execution of your if statement.

You will have to modify your condition to reflect a value depending on what you wish to accomplish.

Good luck!