When to work with 'new' and 'delete'

Question

How do I decide if I create objects on the stack or on the heap? Are there any guidelines, any rules of thumb?

Answer 1

HonFu few compiler allows this and few don't allow... better not to go with array if size is allocated dynamically...

c++ expect that size must be known at compile time... that's the reason few compiler don't allow below also:
int n = 10;
int array[n];

reason is that size is variable and it can be changed... so , with above scenario also, you need to define const int n = 10.

to conclude, array is not to be used for variable sizes.. use array pointer with new operator or else go with vector from STL

Answer 2

HonFu some thing you can decide at run time should be done using new and will get stored in heap

Answer 3

https://medium.com/fhinkel/confused-about-stack-and-heap-2cf3e6adb771

Answer 4

Heap should be used in cases when the size of data isn't known at compilation time (for example the length of an array is given by argument).

Answer 5

Okay, that totally makes sense.

One more piece in the right place, thanks! :)

Answer 6

Ketan, Sergey, now I remember having read that you can not easily define an array 'pythonicly' by cin >> x; ar[x] or something like that (except with the heap stuff).

I tried it on sololearn, it worked, I was like 'huh?' and forgot about it.

So that doesn't work with a compiler, but can work on sololearn only because of the special pre-input situation here?