Pointer is an address, the location of what we're pointing to.
void pointerBasic() {
int x=3;
cout << "x=" << x << '\t' << "&x=" << &x << endl;
int *y = new int(5);
cout << "y=" << y << '\t' << "&y=" << &y << "\t*y=" << *y << endl;
// y is not int, y is a pointer (i.e. address), y has an address too
Array name is also a pointer. It is the starting address of the array. However, array name can not be changed. In other words, it is a "constant pointer".
int A[5] = {10,20,30,40,50}; // static array with initialization
cout << "A=" << A << " &A=" << &A << " *A=" << *A << endl;
cout << "A0=" << A[0] << endl;
Instructions A++ or ++A will generate a compiler error because A is "constant". It can not be changed.
cout << "A+1=" << A+1 << '\t' << "*(A+1)=" << *(A+1) << '\t' << "*A+1=" << *A+1 << endl;
// note pointer+1 is actually increment by 4 (the sizeof int), so the meaning is increment by one element.
// A+2 is the same A[2], points to the 2nd element
void pointerMath(){
int *p = new int[5]; // how does p differ from y above? int *y = new int(5);
cout << "p=" << p << " &p=" << &p << endl;
int *tp = p;
for (int i=1; i<=5; tp++, i++)
*tp=(i)*111;
// pointer math is element based, sizeof(element)
int x=3;
x = *(--tp);
x= *(p+2);
tp = p; // two pointers to one object
delete(p);
x=*tp; // dangling pointer is dangerous
}