Pointers

Pointers and structs

Recall structures

• Defining:

  struct Address {
      string city;
      int zip;
  };
  
  struct Student {
      int id;
      Address addr;
  };

• Using:

  Student pupil;
   
  pupil.id = 98765;
  pupil.addr.city = "Madison";
  pupil.addr.zip = 53713;
   
   
   
   
   
  

Pointers to structs

• Declaring

   

• Dynamically allocating space

   

• Assigning to

   

   

   

   

   

   

   

• Dynamically deallocating space

   

Pointers and arrays

int a[10];
 
int *p = new int[10];
 
for (int i = 0; i < 10; i++) {
    p[i] = i;
    a[i] = 2*i;
}
 
int *q = a;

Pointers and const

 
const int *p
 
 
int * const p
 
 
const int * const p
 
 

Pointer caveats

• Be careful with testing for equality

   

• Don't dereference uninitialized pointers

   

• Don't dereference NULL pointers

   

• Don't dereference deleted pointers

   

• Watch out for memory leaks