In-class notes for 09/28/2018

CS 251 (SD), Fall 2018

• HW9

Reading questions

• Some uses for pointers:

  • Data structures, e.g., array of Dog

  • Linked structures; loops, functions, etc.

  • Dynamic allocation

References vs. address operators

• L-values (left/location) vs. R-values (right)
  Spec for = operator.

  = (Assignment operator)

  • 2 arguments: An L-value (memory location) of type T, and a value of that type T

  • State change: The value arg2 is assigned to the location arg1.

  • Return: Type T, the value that was assigned (i.e., arg2).

• types vs operators (functions with specialized syntax)

Puzzles

HW10

Upcoming topics

• Dynamically allocated memory

  • Preview: 3 ways to allocate memory (i.e., set aside for a particular use, such as a variable.

    • local -- allocated in a stack frame when the program runs (runtime).
      Includes local variables (e.g., within main() or another function), function arguments

    • global -- allocated at compile time. Any memory allocated outside of a function.

    • dynamic -- allocated at runtime in the heap (not part of a stack frame, though a local variable may point to it)

• struct data structures