COSC-1337 Chapter 3

Question 1

“Prompt”

Answer 1

Lets the user know that input is expected and prompts them as to what they must enter.

A cin object must always be preceded by a “prompt”

Question 2

What symbol is this? - “»”

Answer 2

Stream-extraction Operator

Question 3

Gathering input from a users requires what process?

Answer 3

1. “Prompting” the user to enter input

2. Using cin object to read input from the keyboard

Question 4

“Input Buffer” or “Keyboard Buffer”

Answer 4

This is an area of memory where input from the keyboard is temporarily placed before it is converted to the correct value and stored in its variable.

Question 5

What is an “Expression”?

Answer 5

Is something that can be evaluated to produce a single value.

Question 6

“Associativity”

Answer 6

is the order in which an operator works with its operands. It is either left-to-right or right-to-left.

Question 7

What is this for?: algebra = pow(4.0, 2);

Answer 7

It is the variable algebra that has an expression of 4 being raised to the second power.

Question 8

What header file must be included in order to use the pow function?

Question 9

What is “type coercion”?

Answer 9

When C++ automatically converts two values to the same type when used with an operator.

Question 10

char, short, and unsigned short are automatically converted to which type?

Answer 10

int data type

Question 11

An operator working with a lower value data type and a higher value data type will be promoted to what data type?

Answer 11

The higher value variable data type

Question 12

When the final value of an expression (with an operator) is assigned to a variable what happens?

Answer 12

It is converted to the data type assigned to the variable

Question 13

What happens when a floating point number is converted to an int?

Answer 13

It is “truncated” and the decimal gets left out

Question 14

A ________ lets you manually promote or demote a value

Answer 14

“type cast expression”

Question 15

What does this do?: static_cast(Value)

Answer 15

This is type conversion. It can be used to convert the data type of a variable to another.

Question 16

What type cast is this?: pennies = (double)dollar;

Answer 16

Prefix Notation

Question 17

What type conversion is this?: pennies = float(dollar);

Answer 17

Functional notation

Question 18

High-order Bit

Answer 18

It is the leftmost bit. If it is 1 the number stored is negative. If it is 0 the number stored is positive.

Question 19

What is a named constant/variable constant and how is it declared?

Answer 19

It is a variable who has a “read-only” value stored in its memory. You declare it by using “const” before declaring your variable.

Question 20

How would you assign a value to multiple variables at once?

Answer 20

a = b = c = d = e = 12;

Question 21

What direction are assignment operations carried out in?

Answer 21

Right to left

Question 22

How do we write a stream manipulator?

Answer 22

setw(number)

Question 23

What is the setprecision manipulator and how do we use it?

Answer 23

It is used to specify how many decimals we would like to be included in our cout display. It can be used as such - cout &laquo_space;setprecision(number) &laquo_space;variable;

Question 24

How would we a float number display only 4 digits after the decimal?

Answer 24

cout &laquo_space;fixed &laquo_space;setprecision(4) &laquo_space;variable;

Question 25

How would we display the digits after a decimal even if they are zeros?

Answer 25

cout &laquo_space;fixed &laquo_space;showpoint &laquo_space;setprecision(number) &laquo_space;variable;

We would use the showpoint manipulator

Question 26

What header file is needed for setw and setprecision?

Answer 26

The header file iomanip

Question 27

What manipulators remain in effect till the programmer changes them?

Answer 27

setprecision, fixed, showpoint

Question 28

When is showpoint not needed in your source code?

Answer 28

When fixed and setprecision are already being used.

Question 29

How would you make text be left or right justified?

Answer 29

You would use the “left” or “right” manipulator

Question 30

How do we input a string?

Answer 30

getline(cin, variable);

Question 31

What is a member function of cin?

Answer 31

“get” is a member function of cin

Question 32

What does cin.get(variable); do?

Answer 32

It will receive any character as input EVEN A WHITESPACE OR THE ENTER KEY!

Question 33

How do we skip or “ignore” characters?

Answer 33

cin.ignore(n, c);

This will make the program skip “n” number of characters OR to include everything until character “c” is encountered

Question 34

How do we find out the length of a string literal?

Answer 34

variable.length();

Question 35

How do we assign 22 spaces to the variable named x?

Answer 35

x.assign(22, ‘ ‘);

Question 36

What is a C-string and how can we write one?

Answer 36

It is essentially an array. It was the way that C used to store string literals.

char example[10] = “Timmy”;

Question 37

How would we assign a string to a c-string?

Answer 37

We would need to use “strcpy”.

char example[32];

strcpy(example, “This is our c-string text”);

Question 38

How do we give a c-string memory bytes?

Answer 38

With the “size declarator”

Question 39

What are two ways that we can prevent buffer overrun?

Answer 39

1. setw();

2. cin.width();

Question 40

What header file must we include to be able to use the rand() function?

Answer 40

cstdlib

Question 41

How would we generate a random number based on the input from the user?

Answer 41

By creating a variable that would store the input “seed” value and then using the “stand(variable);” function to start the algorithm with the input “seed”.

Question 42

How would you randomly generate a seed without user input?

Answer 42

You would use the “time” function AND you would pass a “0” to its argument

Question 43

What header file must be included to use the time function?

Answer 43

ctime

Question 44

How would we get a random number generated between 10-25?

Answer 44

int x;

x = srand(seed) % (MAX - MIN + 1) + MIN;