Adding an item to an associative array

//go through each question
foreach($file_data as $value) {
   //separate the string by pipes and place in variables
   list($category, $question) = explode('|', $value);

   //place in assoc array
   $data = array($category => $question);
   print_r($data);

}

This is not working as it replaces the value of data. How can I have it add an associative value each loop though? $file_data is an array of data that has a dynamic size.

Answer

I think you want $data[$category] = $question;

Or in case you want an array that maps categories to array of questions:

$data = array();
foreach($file_data as $value) {
    list($category, $question) = explode('|', $value, 2);

    if(!isset($data[$category])) {
        $data[$category] = array();
    }
    $data[$category][] = $question;
}
print_r($data);