Associative Array
Priya only reaches for Associative Array when $student['roll'] has to stay correct in a class list.
Associative Array order — meaning → ['name'=>'Asha','roll'=>12] → one limit. Dumping ten features helps nobody.
Associative Array exists so Priya can keep $student['roll'] correct in a class list.
Use Associative Array when $student['roll'] must stay clear. If a simpler PHP step works, use that instead.
Associative Array trap — mixing 0-based and named keys blindly. Priya loses marks for that every viva.
Associative Array is not a lonely heading. Priya ties it to $student['roll'].
Close Associative Array with: “If I skip it, $student['roll'] goes wrong like this: mixing 0-based and named keys blindly.”
For Associative Array: definition + a class list + one failure.