Ch 1: Review & Intro

Question 1

what is ifstream & ofstream? (what do you use them for, how do you use them - functions)

Answer 1

ifstream & ofstream are file input streams that write to (ofstream) and get data from (ifstream) file inputs

Question 2

what do you use ifstream & ofstream operators and how do you use them?

Answer 2

• use insertion&raquo_space; and extraction &laquo_space;operators to get and write data
• use similarly to cin: inFS», outFS«
• # include

Question 3

what is a pointer and what does the data type of the pointer do?

Answer 3

• pointer: holds a memory address
• pointer data type determines what type of address the pointer will store (Ex. int* p points to address of an int variable)

Question 4

what is a reference(&), what are the dereference operators and what do they do?

Answer 4

• reference(&): obtain a variable’s address
• dereference operators: *, ->, []
• dereference operators retrieve the data from the variable that the pointer points to (Ex. int a = *p, sets a to the data that pointer p points to)

Question 5

what is the new operator?

Answer 5

new operator allocates memory into heap before calling constructor (ex. Point* point1 = new Point(___); )

Question 6

what is the delete operator?

Answer 6

delete operator frees memory of variable in heap

Question 7

how is an allocated array deleted?

Answer 7

delete[]

Question 8

what is the advantage of linked lists over sequential storage approaches (arrays or vectors)?

Answer 8

items can be reordered, added and removed in linked lists without having to shift items

Question 9

what is recursion?

Answer 9

calling the same algorithm(function) multiple times for smaller sets

Question 10

what are the two functions for recursion?

Answer 10

• outer: the function that is called from other parts of the program, calls the inner function
• inner: called by the other function, does recursive action

Question 11

what is an ADT, or abstract data type?

Answer 11

a data type whose creation and update are constrained to specific well-defined operations

Question 12

do variables have to be declared before being used in class definition? how does this relate to inline member functions?

Answer 12

no, variables can be declared after its use in class definition. this relates to inline member functions because sometimes an inline member function calls on a variable that is defined afterwards, but the function definition is still valid

Question 13

what is 100% code coverage?

Answer 13

every line of code is conducted

Question 14

what are border cases?

Answer 14

unusual or extreme test case values

Question 15

how does 100% code coverage relate to bugs in code?

Answer 15

100% code coverage does not ensure that there are no bugs in code

Question 16

what is regression testing?

Answer 16

retesting an item like a class anytime the item is changed

Question 17

what is compile-time polymorphism?

Answer 17

when the compiler determines which function to call at compile-time

Question 18

what is runtime polymorphism?

Answer 18

when the compiler is unable to determine which function to call at compile-time so the determination is made while the program is running

Question 19

what is derived/base class pointer conversion? give an example

Answer 19

a pointer to a derived class is converted to a pointer to the base class without explicit casting- will call the function related to the vector list type instead of the item type
ex. buisnessList.push_back(restaurantPtr); -> restaurant pointer is converted to business pointer

Question 20

what does “override” do?

Answer 20

indicates that a virtual function in base class is overridden in derived class

Question 21

how is runtime polymorphism used without virtual and override?

Answer 21

runtime polymorphism wrks by using reference
ex. PrintDescription(restaurant); -> restaurant is passed by reference so functions called in PrintDescription will be from restaurant class, not business class (if there’s a printName function called in print description then it will call restauran’ts printName not business’s printName)

Question 22

what is an abstract class?

Answer 22

• a class that guides the design of a subclass but cannot itself be instantiated as an object
• has at least 1 pure virtual function
• concrete class is the opposite of abstract

Question 23

what is a pure virtual function

Answer 23

• a virtual function that is not implemented in the base class
• virtual funcName () = 0;
• in base class

Question 24

what is “this”?

Answer 24

used to get an object’s data member, points to the current object

Question 25

what is “Big Oh”?

Answer 25

• formalized way to describe complexity
• figures out how much a program function is going to “cost”
• gives upper bound b/c we don’t care about constants, an overestimation