CS Week 3 - Classes I

Question 1

what is a strut

Answer 1

struct name {
type item;
….
};
—- in main —
name object;
object.item;

Question 2

data member

Answer 2

each struct sub item

Question 3

member access

Answer 3

dot notation
.
for a declared variable, each struct data member can be accessed using .

Question 4

how can use structs and functions

Answer 4

to return multiple values
function return type is struct name
pass in a regular argument
create another object in order to return it

Question 5

how can you use structs and vectors

Answer 5

declaration of just one vector that stores items that each have a name and number data member

Question 6

how to declare a constructor the professor way

Answer 6

name()
: item(iniValue), …. {
}

name (type item, …)
: item(iniValue),… {
}

Question 7

how do you use a private data in main

Answer 7

in struct
type getName() const {return Name};
- usually all in one line

in main
cout &laquo_space;getName();

Question 8

how do you set private data from main

Answer 8

in struct
void setName(type nameInput) {
name = nameInput;
}

in main
object.setName(input);
cout &laquo_space;getName;

Question 9

difference between classes and structs

Answer 9

struct - default everything is public

class- default everything is private

struct is when you have no accessors or methods/functions needed

Question 10

what is an object

Answer 10

a grouping of data - variables - and operations that can be performed on that data - functions

Question 11

what is abstraction

Answer 11

to have a user interact with an item at a high level, with lower level internal details hidden from the user
-information hiding, or encapsulation

Question 12

what is abstractions data type (ADT)

Answer 12

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

Question 13

class

Answer 13

defines a new type that can group data and functions to form an object

Question 14

public member functions

Answer 14

indicate all operations a class user can perform on the object

Question 15

private data members

Answer 15

variables that member functions can access but class users cannot

Question 16

function declaration

Answer 16

return type, function name, and parameter types;

Question 17

function definition

Answer 17

return type className :: functionName (parameters) {
statements ;}

Question 18

mutator

Answer 18

modify data
sets the value

Question 19

accessors

Answer 19

accesses, not to modify
gets the value
const after parameters
if it calls other functions, those must also be const

Question 20

private helper functions

Answer 20

to help public functions carry out tasks
any in the class can call these
private and public can call public and private

Question 21

how to initialize data members

Answer 21

in the class definition
…
private :
string name = something;
int num = something;
};

or constructors

Question 22

what is a constructor

Answer 22

called automatically when a variable of that class type is declared and which can initialize data members

Question 23

what is a default constructor

Answer 23

no arguments

className :: className () {
set the variables equal to something here;
}

Question 24

overload

Answer 24

by defining multiple constructors differing in parameter types

class name{
public:
//sets to default value
name ();

        //sets to input values when called
     name (parameters that will be set to the private varibales); ... };

Question 25

implicit parameter

Answer 25

object.Function();

object variable before the function name

compiler converts the call into a function call with a pointer to the object implicitly passed a parameter

Question 26

member access operator

Answer 26

->
this->
makes it clear that a class member is being accessed and is essential if data members and parameters have the same identifier

• when an objects member function is called, objects memory address is passed via the implicit this parameter