Array

Don’t start Array with jargon. Start with $student['roll']. That is the whole point.

Keep Array small. Arun should finish $student['roll'] in a few lines, not a 40-line dump.

Skip Array and mixing 0-based and named keys blindly shows up in a class list.

Use Array when $student['roll'] must stay clear. If a simpler PHP step works, use that instead.

Array miss — mixing 0-based and named keys blindly. Fix it before you talk about advanced PHP.

Array is not a lonely heading. Arun ties it to $student['roll'].

Viva for Array — what it is → ['name'=>'Asha','roll'=>12] → the mistake (mixing 0-based and named keys blindly).