Doubt regarding passing by reference and passing normally

#1

i wanted to ask one thing that in the cases when we don’t pass the root node by reference what actually happens there.
how are we able to change a old values then like we did in the case of the sum replacement .
or some copy is being created there.
kindly clear this doubt like how can we update the value if it is not passed by reference .

#2

hello @saurabh66
we are sending pointer right? i.e we are sending pointer which has address of node. so with the help of that pointer we can manipulate data