W11 quiz: cstring, optparams, structs

Question 1

Like variables, the contents of an array could be any values until/unless we specifically store something. The first time we store a value in an array position we are initializing that array element.

_ True?
_ False?

Answer 1

True

Question 2

The update statement is performed at the bottom of a for loop, just after
each pass through the body.

_ True?
_ False?

Answer 2

True

Question 3

What output is produced by the segment of code shown below:

for (int i = 1; i <= 10; i = i + 2)
{
cout &laquo_space;i;
}

a: 13579
b: 1357
c: 12345678910
d: 13578

Answer 3

a: 13579

Question 4

What loos needs a semi-colon after?

a: do
b: while
c: all of the options listed
d: for

Answer 4

a: do

Question 5

What is the output of the following program:

int main()
{
int myArray[4] = {77, 33, 44, 8};

    for(int i=0; i < 4; ++i)
    {
            cout << myArray[i];
    } } a: 7348 b: None of the options listed c:8443377  d: 7733448

Answer 5

d: 7733448

Question 6

In nested loops, the outer loop runs to completion first (likely multiple times)
before the inner loop is executed.

_ True?
_ False?

Answer 6

False

Question 7

The following code will produce an infinite loop:

int main()
{
int i = 10;
while(i<100)
{
cout &laquo_space;i &laquo_space;endl;
}
}

_ True?
_ False?

Answer 7

True

Question 8

What loops are guaranteed to execute at least once?

a: while
b: none of the options listed
c: do
d: for

Answer 8

c: do

Question 9

An array is organized into positions, each acting as a storage spot for one item.
_ True?
_ False?

Answer 9

True

Question 10

What are the 2 expanding ways that we can declare and call functions?

Answer 10

optional parameters and function overloading

Question 11

Is it possible to provide default values for a parameter?

Answer 11

Yes

Question 12

What option can the caller have with the parameter?

Answer 12

The caller has the option of calling the function with or without passing that specific parameter

Question 13

Is it possible to declare multiple different versions of a function with the same name?

Answer 13

Yes

Question 14

What is the condition for declaring multiple different versions of a function with the same name?

Answer 14

The parameter lists are “different enough” for the compiler to always identify the correct one to call

Question 15

Can we assign a default for one or more parameters in the declaration?

Answer 15

Yes,
example:
void myfunction(int x, char y = ‘a’, float z = 1.3)
note: must be done in the prototype when following the course code standards

Question 16

Can the caller omit one or more of the parameters?

Answer 16

Yes
example:
myfunction(10); // uses ‘a’ for y, 1.3 for z
myfunction(10, ‘q’); // uses 1.3 for z

Question 17

What is the order of parameter assignment?

Answer 17

left-to-right order
example:
void myfunc(int x=1, int y=2, string z=”boo”);
● myfunc(3); // always gets assigned to x

Question 18

Can you choose to use a default value for a “middle” parameter and pass a value for a later one?
ex:
myfunc(0, “hello); // tries to assign “hello” to y

Answer 18

No, it does not work

Question 19

Can we declare multiple functions with different names?

Answer 19

No, we cannot. We have to declare multiple functions with the same name

Question 20

If you declare multiple functions with the same name, what is another condition so that it works?

Answer 20

The number/types of parameters have to be unambiguous. e.g.
void printDate(string date);
void printDate(int yy, int mm, int dd);
void printDate(string weekday, string month, string day);

Question 21

the compiler decides which to use based on params only, what do these lines mean?
void f1(int x);
int f1(long y);

Answer 21

// later called with int i = f1(3)
// gives error, f1 void

Question 22

void f1(int x);
int f1(int y, string z=”boo”);
f1(10); // could mean either one

explain what the codes are saying?

Answer 22

when functions include optional parameters then you must also account for any possible combination of passed parameters when considering the ambiguity

Question 23

include <iostream></iostream>

#include <string>
using namespace std;
void printDate(int mm, int dd=1);
void printDate(string wkday=”Monday”);
int main()
{
printDate(10,31);
printDate(); //1 meaning?
printDate(“Tuesday”);
printDate(7); //2 meaning?
}
void printDate(int mm, int dd)
{
cout << mm << “/” << dd;
}
void printDate(string wkday)
{
cout << wkday;
}</string>

Answer 23

//1: uses “Monday”
//2: uses 7, 1

Question 24

What is the format of a function definition?

Answer 24

return-value-type function-name (parameters list)
{ declaration and statement }

Question 25

Can a function be declared inside another function?

Answer 25

Under any circumstances, the answer is still no

Question 26

what does the return-value-type Void indicate?

Answer 26

It indicates that a function does not return a value

Question 27

Which type of value will be assigned for a function if it does not declare its return-value-type?

Answer 27

int

Question 28

How is a function with empty parameter lists expressed?

Answer 28

void print(); //does not take in any argument

Question 29

function overloading:

Answer 29

must have different parameters

Question 30

What is the technical difference between structs and classes?

Answer 30

the only technical difference between a c++ class and a c++ struct is that structs declare/inherit things publicly by default, whereas classes declare/inherit them privately by default

Question 31

What is the convention for using structs and classes?

Answer 31

programmers use 2 quite differently: structs being used purely as data containers, and classes being used where we wish to incorporate more advanced functionality

Question 32

What do structs allow us to do?

Answer 32

structs allow us to group elements of different data types into a single logical entity

Question 33

When we define structs, are we defining a new data type?

Answer 33

Yes

Question 34

What is the syntax of a struct?

Answer 34

we specify a new type name, plus types and names for each of the individual fields
Ex:
struct productInfo
{
string name;
float price;
}

Question 35

Can a struct be a parameter value?

Answer 35

Yes it can, a function can have structs as parameters

Question 36

How can a function change the content of a struct?

Answer 36

The struct must be passed by reference

Question 37

Where can a struct be stored?

Answer 37

In arrays

Question 38

An example of struct use

Answer 38

productInfor p;
cout &laquo_space;“Enter the product name and price” &laquo_space;endl;
cin&raquo_space; p.name&raquo_space; p.price;
cout &laquo_space;p.name &laquo_space;” $” &laquo_space;p.price &laquo_space;endl;

Question 39

How do you access structure members?

Answer 39

Use the dot syntax (.)

Question 40

What is the name for specifying more than one function of the same name in the same scope?

Answer 40

function overloading