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.

You can simply do this

$data += array($category => $question);

If your're running on php 5.4+

$data += [$category => $question];

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);

before for loop :

$data = array();

then in your loop:

$data[] = array($catagory => $question);

I know this is an old question but you can use:

array_push($data, array($category => $question));

This will push the array onto the end of your current array. Or if you are just trying to add single values to the end of your array, not more arrays then you can use this:

array_push($data,$question);

For anyone that also need to add into 2d associative array, you can also use answer given above, and use the code like this

 $data[$category]["test"] = $question

you can then call it (to test out the result by:

echo $data[$category]["test"];

which should print $question