C ++ learning notes (1) pointer: learning notes pointer

C ++ learning notes (1) pointer: learning notes pointer

Pointer Reference

1 int I = 1; 2 int * p; 3 int * & r = p; // r is a reference to pointer p 4 r = & I; // r is a reference to p, so the value assigned to r is that p points to i5 * r = 2; // update the I value

 

• You can update the value pointed to by the pointer in * p mode.
• You can declare a reference to the pointer and perform related operations on behalf of the pointer.

Pointer to a constant

1 const double pi = 3.14; 2 const double * ptr = & pi; // correct 3 double * err = & pi; // error, err is a normal pointer

• The pointer type must be the same as the indicated type. But there are exceptions
  • Allows a pointer pointing to a constant
  • The object indicated by a pointer to a constant may not be a constant.