Quiz 2

Question 1

Stack-allocated variables continue to exist even after the function where they were created returns

True
False

Answer 1

False

Question 2

Does a variable allocated using malloc() need to be deallocated by the programmer?

No, the OS takes care of deallocating them

No, the compiler takes care of deallocating them

Yes, using the unmalloc() function call

Yes, using the free() function call

Answer 2

Yes, using the free() function call

Question 3

In C, the programmer is responsible for deciding whether a variable is stored in memory or a CPU register

True

False

Answer 3

True

Question 4

C is a compiled language

True
False

Answer 4

True

Question 5

The snippet below always prints “True”:

if ( 1 )
printf(“True”);
else
printf(“False”);

True
False

Answer 5

True

Question 6

The snippet #define min(a, b) (a < b ? A : b) defines a preprocessor _____ . It is similar to a function, but may be faster than a function call.

Answer 6

The snippet #define min(a, b) (a < b ? A : b) defines a preprocessor macro. It is similar to a function, but may be faster than a function call.

Question 7

Select all the memory regions where pointers can be allocated from a C program

Storage

Heap

Swap

Stack

Answer 7

Heap

Stack

Question 8

What is the result of the command below?

gcc -o myfile myfile.c

The compiler returns an error due to incorrect command line parameters

“myfile.c” gets overwritten by an executable program called “myfile”

“myfile.c” gets compiled to an executable file called “myfile.out”

“myfile.c” gets compiled to an executable program called “myfile”

Answer 8

“myfile.c” gets compiled to an executable program called “myfile”

Question 9

The following command is the correct one to compile “example.c”:

gcc -o example.c example

True
False

Answer 9

False

Question 10

What happens if I run “int* ptr = 0; *ptr = 42;” ?

The value pointed at by ptr is set to 0

The value pointed at by ptr is set to 42

Nothing; the code does not compile

Segmentation fault (the program crashes)

Answer 10

Segmentation fault (the program crashes)

Question 11

A C header file typically has extension . ______(50 %) . In order to use header files in source code, they must imported using the # ______(50 %) preprocessor directive.

Answer 11

A C header file typically has extension . ___h___(50 %) . In order to use header files in source code, they must imported using the # ___include___(50 %) preprocessor directive.

Question 12

What is the correct way to modify the location stored by the “myptr” pointer?

*myptr = 42;

&myptr = 42;

myptr = 42;

%myptr = 42;

Answer 12

myptr = 42;

Question 13

What is a concrete, unambiguous difference between C and Python?

C is compiled, Python is interpreted

C can be used to read/write files, Python cannot

C is fast, Python is slow

Python allows to divide a program in multiple source files, C does not

Answer 13

C is compiled, Python is interpreted

Question 14

Memory for variables stored on the heap must be manually allocated using the ______ function.

Answer 14

Memory for variables stored on the heap must be manually allocated using the ___malloc___ function.

Question 15

In C, what does the following snipped do?

register int myvar = 42;

Tell the compiler that myvar should be stored in a register

Tell the preprocessor to replace every instance of the string “myvar” with the string “42”

Write the value 42 into all CPU registers

Tell the compiler to move myvar out of a register

Answer 15

Tell the compiler that myvar should be stored in a register