C quiz

#include <stdio.h>

int main() {

int arr[] = {10, 20, 30, 40, 50};

int *ptr = arr;

ptr = ptr + 2;

printf("%d ", *(ptr + 1));

return 0;

}

• 30

• 40

• 50

• 20

#include <stdio.h>

#include <string.h>

int main() {

char str[] = "Hello, world!";

printf("%d", strlen(str));

return 0;

}

• 13

• 14

• 12

• Undefined behaviour

#include <stdio.h>

#include <stdlib.h>

int main() {

int *arr = (int *)calloc(3, sizeof(int));

arr[1] = 10;

arr[2] = 20;

free(arr);

printf("%d", arr[2]);

return 0;

}

• 0

• 10

• 20

• Undefined behavior

#include <stdio.h>

#include <stdlib.h>

int main() {

int *arr = (int*)malloc(10 * sizeof(int));

free(arr);

arr[0] = 5;

printf("%d", arr[0]);

return 0;

}

• It will print 5.

• It will print 0.

• It will give a runtime error due to accessing freed memory.

• It will give a compilation error.

#include <stdio.h>

int main() {

int x = 5; // Binary: 0101

x = x << 1;

printf("%d", x);

return 0;

}

• 5

• 10

• 20

• 2

#include <stdio.h>

struct Person {

char name[30];

int age;

}

int main() {

struct Person persons[2] = {{"John", 25}, {"Jane", 30}};

printf("%d", persons[1].age);

return 0;

}

• persons[1].name

• persons[0].age

• persons[1].age

• persons[0].name

#include <stdio.h>

int main() {

for (int i = 0; i >= 0; i++) {

printf("%d ", i);

}

return 0;

}

• The loop will terminate after one iteration.

• The loop will run forever.

• The loop will run 0 iterations.

• It will cause a segmentation fault.

#include <stdio.h>

void changeValue(int *x) {

*x = 10;

}

int main() {

int num = 5;

changeValue(&num);

printf("%d", num);

return 0;

}

• 5

• 10

• Compilation error

• Undefined behavior

#include <stdio.h>

int main()

{

int x = 5;

x = x ^ 3;

printf("%d", x);

return 0;

}

• 125

• 2

• 8

• 15

#include <stdio.h>

void func() {

static int x = 5;

printf("%d ", x);

x++; }

int main() {

func();

func();

func();

return 0;

}

• 5 5 5

• 5 6 7

• 6 6 6

• Compilation error