C++ POINTERS

Question

Hi, I wanted to ask a couple of questions about some things I didn't understand about pointers in c ++.
1) What are they for, and if you can give me examples of programs, where pointers are
necessary;
2) If they are useful in 2020;
3) When for example in the C ++ code I declare a variable like *p = &a. This contains the
memory address of the variable 'a', and I wanted to know if this address (I HAVE USED
VISUAL STUDIO), is that of the memory of my computer or one chosen at random
from visual studio;
I sincerely thank anyone who will help me solve this problem

Answer 1

For example, if we are making dynamic array, and we want user to declare size of it
int a;
cin >> a;
int tab[a];
Code above will result in error. We need to use pointer instead of tab[a] like this:
int * tab = new int[a] ;

There are plenty of examples on how useful pointers are, you can just type in browser for "pointers usage"

Answer 2

pointer is a base in c++. they are used everywhere!!!

Answer 3

ok thanks