C Pointers Quiz

Example Questions From the Test

• 1If p has type int *, which statement idiomatically allocates enough space for five int elements?
  • Scale by the pointed-to type: p = malloc(5 * sizeof *p);
  • Request only five bytes: p = malloc(5);
  • Use the size of the pointer: p = malloc(sizeof p);
  • Use five pointer-address sizes: p = malloc(5 * sizeof &p);
• 2Given the declaration int n;, which operation obtains the memory address of n?
  • Dereference n with *n
  • Apply array notation with n[]
  • Measure the object using sizeof n
  • Apply the address operator as &n
• 3A function is declared void swap(int *x, int *y);. Which call lets it exchange the values of int variables a and b?
  • Use swap(*a, *b), attempting to dereference the integers
  • Use swap(a, b), passing the integer values directly
  • Use swap(&a, &b), passing both variable addresses
  • Use swap(&a, b), passing one address and one value