References and Pointers

Question 1

give existing variables new names
allow modification of arguments or items
avoid copying data

Answer 1

references

Question 2

the original iterator

Answer 2

pointers

Question 3

int x = 5;
int y = x;
what is the value of y?

Answer 3

5

Question 4

int x = 5;
int y = x;
y = 10;
what is the value of x now?

Answer 4

5

the line y = x; copied the value of x into y

Question 5

the blank makes a reference

Answer 5

& ampersand;

Question 6

a reference is a blank

Answer 6

new name for something

Question 7

True or False

you can change what a reference refers to after it is created

Answer 7

False

Question 8

One of the main places we use references is with blank

Answer 8

function arguments

Question 9

why is the argument for print_vector both const and a reference?

Answer 9

a const reference argument avoids the cost of copying the vector, but does not allow the vector to be accidentally modified by the function

Question 10

blank is usually the right way to pass an argument

Answer 10

const reference
unless
the function needs to modify the variable passed in
the argument has a simple data type, such as int or double

Question 11

References can be used with blank to allow modification to the value of the items in the container:

Answer 11

range-style for loops

Question 12

references and range-style for loops

Answer 12

for(int&x : numbers)
{
x = x * 2;
}

for (pair& p : scores)
{
p.second = p.second + 5.0;
}

**no need for iterators

Question 13

blank is like a big vector of bytes

Answer 13

memory

Question 14

each byte has an address; the first byte is blank, the second is blank, etc

Answer 14

first byte is 0

the second byte is 1

Question 15

Each object is given a blank of those bytes to store its value

Answer 15

subsequence
ex: an int is given 4 bytes
a double is given 8 bytes

Question 16

the address of an object is the address of its blank

Answer 16

first byte

Question 17

blank is a variable that holds the address of an object in memory

Answer 17

pointer

Question 18

blank can refer to another variable

Answer 18

pointer

Question 19

to declare a pointer, use blank after the type

Answer 19

*

Question 20

int x = 5;
int* y;
y = &x;
what does that do

Answer 20

int x = 5 is a regular integer
int* y; pointer to an integer
y = &x make y point at x

Question 21

when you are done with the ptr data, be sure to release it with blank

Answer 21

delete

delete x;

Question 22

pointers can be made to point at entirely new data using the blank keyword

Answer 22

new

Question 23

data allocated by new is allocated in an area called blank

Answer 23

free store

Question 24

containers like string, vector, and map place their contents in the blank

Answer 24

free store

Question 25

most variables are allocated at the end of memory in an area called the blank

Answer 25

call stack

Question 26

data in the free store remains allocated until we use the blank key word

Answer 26

delete key word

Question 27

blank allow you to access and modify another variable

Answer 27

pointers and references

Question 28

require special syntax

Answer 28

pointers
such as * deference operator
such as & (address-of operator)

Question 29

can be moved to point at a new variable

Answer 29

pointers

Question 30

can reference to entirely new data

Answer 30

pointers

Question 31

also available in pure C

Answer 31

pointers

Question 32

no special syntax

Answer 32

references

Question 33

cannot change which variable is referred to

Answer 33

references

Question 34

cannot refer to entirely new data

Answer 34

references

Question 35

new to C++

Answer 35

references