CSCI 3110

Pointer Exercises

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1. Given the following code, determine the datatype for each expression:

   int x;
   int* ptr;
   

   Expression	Datatype	Possible Values
   x
   ptr
   *ptr
   &ptr
   &x

2. Add code as directed by the comments to pointersExercise.cpp and execute to see values update:

   int main(){
       int number = -1;
       int* intPtr1;
       int* intPtr2;
   
       // 1) Make intPtr1 point to number
   
       // 2) Assign 3 to the variable that intPtr1 is pointing to (using intPtr1)
       
       // 3) Make intPtr1 point to a newly allocated int
   
       // 4) Assign that new int to 7
       
       // 5) Copy the address stored in intPtr1 to intPtr2
   
       // 6) Make intPtr2 point to a newly allocated int
       
       // 7) Assign that new int to 1
       
       // 8) Free up the allocated memory and set both pointers to nullptr
        
       return 0;
   }
   

3. Diagram the elements on the stack and write the output of the following (adapted from HERE):

   #include <iostream>
   
   int main (){
     int numbers[5];
     int * p;
     
     p = numbers;          *p = 10;
     p++;                  *p = 20;
     p = &numbers[2];      *p = 30;
     p = numbers + 3;      *p = 40;
     p = numbers;      *(p+4) = 50;
     
     for( int n = 0; n < 5; n++){
       std::cout << numbers[n] << ", ";
     }
     return 0;
   }
   
   

4. 1. Declare ex0 as a pointer to a char
   2. Declare ex1 as a pointer to a pointer to a char
   3. Declare ex2 as an array of 10 elements
   4. Declare ex3 as an array of 10 elements that are pointers to chars
   5. Declare ex4 as a pointer to an array of 30 char elements
   6. Declare ex5 as an array of 10 pointers to arrays of 500 char elements
   7. Declare ex7 as a pointer to const int
   8. Write a function ex8 that takes a char pointer named pc, increments the address that it points to and returns that value
   9. Write a function ex9 that takes an int pointer named num, and prints out what num points to and a message saying if what num points to is odd or even
5. Add code as directed by the comments:

   #include <iostream>
   #include <string>
   using std::string;
   using std::cout;
   
   struct Car{
       float price;
       string make;
       string model;
   };
   
   int main(){
       // 1) Allocate memory using new for a Car object and save that
       //    location with a pointer named latestModel.
       
       // 2) Populate each of the members of the struct with appropriate
       //    values of your choice
   
       // 3) Print out the values of the struct
       
       // 4) Print out the memory address of the struct.
       //    Is that address on the stack or the heap?
       
       // 5) Print out the memory address of the pointer.
       //    Is that address on the stack or the heap?
       
       // 6) Free up the allocated memory.
   
       return 0;
   }
   

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