the cherno

Question 1

What is this an example of?
#include <iostream></iostream>

Answer 1

preprocessor statement

Question 2

What does this do?
#include <iostream></iostream>

Answer 2

Copy paste the declarations from iostream.h at the top of the file

Question 3

How does compilation work in C++? Describe all of the steps.

Answer 3

1. Process preprocessor statements
2. Compile all (or selected) files to .obj binaries
3. Linker will combine all .obj files into one .exe or .dll

Question 4

Give an example of a linker error.

Answer 4

A function or type is declared in a header or other declaration, but no definition could be found in the .obj files.

Question 5

1 bit

Answer 5

a 0 or a 1

Question 6

1 byte

Answer 6

8 bits

Question 7

How many unique values can be stored in 10 bytes?

Answer 7

10 bytes = 80 bits = 2^80 unique combinations = 2^80 unique values

Question 8

How to find out what the size of a given primitive type is

Answer 8

sizeof(int)

Question 9

True or false: the size of a long is always the same, regardless of your computer and your compiler.

Answer 9

false! it may differ for different compilers

Question 10

what is the function of the different primitive data labels?

Answer 10

size, and clues for the programmer and language about how to treat it (i.e. when printing)

Question 11

Float vs double

Answer 11

float = 4 bytes, double = 8 bytes

Question 12

To assign a float, you must…

Answer 12

add f to the end of the numeric literal

Question 13

*var

Answer 13

deref the pointer “var” (i.e. access the value)

Question 14

int*

Answer 14

declare a pointer (and we want to treat the value at the address llike an int, but there is no guarantee that it will be one)

Question 15

char&

Answer 15

declares a reference (a wrapper for a pointer that gets one address in its lifetime)

Question 16

&var

Answer 16

access the address of the value var

Question 17

NULL

Answer 17

equivalent to 0

Question 18

Why is this ok?
char* myPtr = &someChar; cout << myPtr << "\n";

Answer 18

char* pointers are treated specially be cout; it will automatically dereferenace it and get the associated char

Question 19

bool

Answer 19

a 1-bit integer. if it is 0, it is fasle, otherwise it is true

Question 20

What will happen when this code is run?
int a = 5;
int b = 8;
int& ref = a;
ref = b;

Answer 20

it will set the value at the address of a to 8. it will NOT change where the pointer points.

Question 21

memset args

Answer 21

memset(address, value, size_of_block)

Question 22

write a method to take in a int pointer, and increment the value that it points to

Answer 22

void increment(int* ptr)
{
(*ptr)++;
}

Question 23

write a method to take in an int by reference, and increment the value

Answer 23

void increment(int& i)
{
i++;
}