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10/10/2020 09:04:37 AM

Câu hỏi trắc nghiệm ngôn ngữ lập trình C (tiếp theo)

Q41:

Code:

 

int x = 3;

if( x == 2 );

  x = 0;

if( x == 3 )

 x++;

else x += 2; 


What value will x contain when the sample code above is executed?
Choice 1
1
Choice 2
2
Choice 3
3
Choice 4
4
Choice 5
5


Q42:

Code:

 

char *ptr;

char myString[] = "abcdefg";

ptr = myString;

ptr += 5; 


What string does ptr point to in the sample code above?
Choice 1
fg
Choice 2
efg
Choice 3
defg
Choice 4
cdefg
Choice 5
None of the above


Q43:

Code:

 

double x = -3.5, y = 3.5;

printf( "%.0f : %.0f\n", ceil( x ), ceil( y ) );

printf( "%.0f : %.0f\n", floor( x ), floor( y ) ); 


What will the code above print when executed?
ceil =>rounds up 3.2=4 floor =>rounds down 3.2=3
Choice 1
-3 : 4
-4 : 3 
Choice 2
-4 : 4
-3 : 3
Choice 3
-4 : 3
-4 : 3
Choice 4
-4 : 3
-3 : 4
Choice 5
-3 : 3
-4 : 4

Q44:
Which one of the following will declare a pointer to an integer at address 0x200 in memory?
Choice 1
int *x;
*x = 0x200
Choice 2
int *x = &0x200;
Choice 3
int *x = *0x200;
Choice 4
int *x = 0x200;
Choice 5
int *x( &0x200 );

Q45:

Code:

 

int x = 5;

int y = 2;

char op = '*';

switch (op)

{

  default : x += 1;

  case '+' : x += y; /*It will go to all the cases*/

  case '-' : x -= y;

} 


After the sample code above has been executed, what value will the variable x contain?
Choice 1
4
Choice 2
5
Choice 3
6
Choice 4
7
Choice 5
8

Q46:

Code:

 

x = 3, counter = 0;

while ((x-1))

{

   ++counter;

   x--;

} 


Referring to the sample code above, what value will the variable counter have when completed?
Choice 1
0
Choice 2
1
Choice 3
2
Choice 4
3
Choice 5
4

Q47:
char ** array [12][12][12];
Consider array, defined above. Which one of the following definitions and initializations of p is valid?
Choice 1
char ** (* p) [12][12] = array;
Choice 2
char ***** p = array;
Choice 3
char * (* p) [12][12][12] = array;
Choice 4
const char ** p [12][12][12] = array;
Choice 5
char (** p) [12][12] = array;

Q48:
void (*signal(int sig, void (*handler) (int))) (int);
Which one of the following definitions of sighandler_t allows the above declaration to be rewritten as follows:
sighandler_t signal (int sig, sighandler_t handler);
Choice 1
typedef void (*sighandler_t) (int)
Choice 2
typedef sighandler_t void (*) (int);
Choice 3
typedef void *sighandler_t (int);
Choice 4
#define sighandler_t(x) void (*x) (int)
Choice 5
#define sighandler_t void (*) (int)

Q49:
All of the following choices represent syntactically correct function definitions. Which one of the following represents a semantically legal function definition in Standard C?
Choice 1

Code:

 

 int count_digits (const char * buf) {

  assert(buf != NULL);

  int cnt = 0, i;

  for (i = 0; buf[i] != '\0'; i++)

    if (isdigit(buf[i]))

      cnt++;

 

 

 return cnt;

} 

 


Choice 2

Code:

 

 int count_digits (const char * buf) {

  int cnt = 0;

  assert(buf != NULL);

  for (int i = 0; buf[i] != '\0'; i++)

    if (isdigit(buf[i]))

      cnt++;

  return cnt;

} 

 


Choice 3

Code:

 

 int count_digits (const char * buf) {

  int cnt = 0, i;

  assert(buf != NULL);

  for (i = 0; buf[i] != '\0'; i++)

    if (isdigit(buf[i]))

      cnt++;

  return cnt;

} 

 


Choice 4

Code:

 

 int count_digits (const char * buf) {

  assert(buf != NULL);

  for (i = 0; buf[i] != '\0'; i++)

    if (isdigit(buf[i]))

      cnt++;

  return cnt;

} 

 


Choice 5

Code:

 

 int count_digits (const char * buf) {

  assert(buf != NULL);

  int cnt = 0;

  for (int i = 0; buf[i] != '\0'; i++)

    if (isdigit(buf[i]))

      cnt++;

  return cnt;

} 

 




Q50:
struct customer *ptr = malloc( sizeof( struct customer ) );
Given the sample allocation for the pointer "ptr" found above, which one of the following statements is used to reallocate ptr to be an array of 10 elements?
Choice 1
ptr = realloc( ptr, 10 * sizeof( struct customer));
Choice 2
realloc( ptr, 9 * sizeof( struct customer ) );
Choice 3
ptr += malloc( 9 * sizeof( struct customer ) );
Choice 4
ptr = realloc( ptr, 9 * sizeof( struct customer ) );
Choice 5
realloc( ptr, 10 * sizeof( struct customer ) ); 

 

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