Radio Button Validation

[Fmdpa]

I know it sounds simple, but I've tried MANY combinations of code, and none of them are successfully checking whether a radio button is selected. I don't want to choose a default radio button, because I want to ensure that the user DOES select an option.

$radio = $_POST['radio_input'];if($_POST['submit']) {	if($radio == '') { //method no. 1		//error   }   	if(($radio != 'option1') && ($radio != 'option2') && ($radio != 'option3')) { //method no. 2		//error   }	if(!$radio) { //method no. 3		//error   }	  	if(empty($radio)) { //method no. 4		//error   }   }

What could be wrong?

[justsomeguy]

It's kind of hard to tell without seeing the form markup, but keep in mind that browsers only submit checkboxes and radio buttons if they are selected. If they are not selected, the browser doesn't even submit something with that name. You can use the isset function to check if something in $_POST is set.

[HungryMind]

Hi!Try as JustSomeGuy Said:

<?phpif(isset($radio)){print "radio button selected";}else{print "radio button not selected";}?>

[justsomeguy]

$radio is always going to be set, you need to check $_POST.

[Fmdpa]

Since $radio is set to the $_POST value, isn't that indirectly checking $_POST? Maybe I should do $radio = isset($_POST['radio']);?

[thescientist]

yes, but that's assuming $_POST is set. That's what you need first before you can start assigning variables from it.

[Fmdpa]

So maybe something like this:

$radio = isset($_POST['radio']) ? $_POST['radio'] : '';

[justsomeguy]

Since $radio is set to the $_POST value, isn't that indirectly checking $_POST?

isset checks if a variable is set. $radio is set to some value from $_POST, which may not be set. If the value in $_POST is not set, $radio will get set to an empty string. So $radio is set, but the value in $_POST is not. So no, it's not indirectly checking if $_POST is set, it's directly checking if $radio is set. The empty function will return true if the value is either not set or empty.

[Fmdpa]

Here's the final working code:

global $radio;$radio = isset($_POST['radio']) ? $_POST['radio'] : '';if ($radio != '') {		switch ($radio) {			case 'landscape':				//process landscape				break;			case 'wildlife':				//process wildlife				break;			case 'other':				//process other				break;		} //end switch statement	} //end radio button processif ($radio == '') {	$errors .= 'Please Select a Category.<br/>';}//end validate