C++ Review

Question 1

Memory

Answer 1

C++ program has two key areas: Stack and Heap

Question 2

Stack

Answer 2

• Manages function calls and control flow, stores local variables, function parameters as local variables, and return addresses
• Each function call creates a stack frame
• Limited in Size
• LIFO (Last-In-First-Out)
• Automatically managed by system
• Everything is destroyed when goes out of scope

Question 3

Heap

Answer 3

• Enables dynamic allocation; a.k.a., allocating memory on heap during runtime
• Larger size
• new keyword to perform allocation
• delete keyword to free memory/prevent leaks

Question 4

Pointers

Answer 4

• Store memory addresses
• Dereferencing to access data at the address
• Ensure type safety
• Pointer Arithmetic to navigate arrays

Question 5

Dynamic allocation

Answer 5

• Allows memory allocation at runtime
• Helpful for large or unknown data sizes
• e.g. size_t array_size; std::cout << "array size: "; std::cin >> array_size; int* array_ptr = new int [array_size] {10}; delete[] array_ptr;

Question 6

Memory Errors

Answer 6

Crucial to for avoid program crashes, data corruption and security vulnerabilities

Question 7

Stack overflow

Answer 7

Exceeding stack size, often by recursion or large arrays

Question 8

Index out of bounds

Answer 8

Accessing an area in memory outside an array’s scope

Question 9

Memory leak

Answer 9

Deleting the reference to your data on the heap so the data is no longer accessible; leading to wasted memory resources and unexpected behavior

Question 10

Dangling pointers

Answer 10

Pointer that points to an address that was previously de-allocated. To avoid this, always set the pointer to nullptr after freeing the memory using delete;
~~~
delete age_ptr;
age_ptr = nullptr;
~~~

Question 11

Use After Free

Answer 11

Trying to access memory after it’s been de-allocated

Question 12

Double Free

Answer 12

double deletion on the same pointer; aka trying to free memory twice

Question 13

Uninitialized memory access / Segementation Fault

Answer 13

int * pointer;
std::cout << *pointer << std::endl;

Question 14

Operator Overloading

Answer 14

Enabling user-defined objects to work with standard operators; e.g., ==, =, >, <, «,&raquo_space;

Question 15

Constructors

Answer 15

Initialize objects. If overloaded, you can create objects under different scenarios based on the parameters

Question 16

“Big 3”

Answer 16

For any class, you should have the Copy Constructor, Destructor, and Copy Assignment Operator

Question 17

Template Functions

Answer 17

• Function blueprint with generic data types
• Compiler generates the actual functions for needed data types based on how the functions are called at compile time!
• Must specify data type in angle brackets
• Following example works for chars, doubles, ints
• `template <typename>
  T max(T a, T b)
  {
  return (a>b) ? a : b;
  }</typename>in main:int x = 5;
  int y = 2;max <int> (x,y);
  `</int>

Question 18

Stack Frame

Answer 18

• Created and pushed onto stack during function call
  *

Question 19

Template Classes

Answer 19

template <typename></typename>