1.
If a variable is a pointer to a structure, then which of the following operator is used to access data members of the structure through the pointer variable?
Correct Answer
D. '->'
Explanation
The '->' operator is used to access data members of a structure through a pointer variable. This operator is used when the variable is a pointer to a structure, allowing us to access the members of the structure using the pointer. It is used to dereference the pointer and access the members of the structure directly.
2.
What will be the output of the program ?
int main()
{
inti=3, *j, k;
j = &i;
printf("%d\n", i**j*i+*j);
return0;
}
Correct Answer
A. 30
Explanation
j=&i implies *j=i;
*j=3
i**j=3*3=9
i**j*i=9*3=27
i**j*i+*j=27+3=30
3.
What will be the output of the program?
int main()
{
void *vp;
char ch=74, *cp="JACK";
int j=65;
vp=&ch;
printf("%c", *(char*)vp);
vp=&j;
printf("%c", *(int*)vp);
vp=cp;
printf("%s", (char*)vp+2);
return 0;
}
Correct Answer
A. JACK
Explanation
The pointer always stores integer value so cp will store the memory address of the location where string "jack " is stored. VP = &ch; Will store address of ch in VP so while we print content in print it will print ASCII value of 74 i.e "J" VP = &j; It will assign address of j to VP again it will print ASCII value of 65 as "A" vp = cp; In this step cp is pointing to memory location where string jack is stored and we r incrementing it by two so it will point to "C" from sring "JACK" and since we have given %S in print so it will print content from c onward ie "CK"
4.
What will be the output of the program ?
int main()
{
inti, a[] = {2, 4, 6, 8, 10};
change(a, 5);
for(i=0; i<=4; i++)
printf("%d, ", a[i]);
return 0;
}
change(int *b, int n)
{
int i;
for(i=0; i<n; i++)
*(b+1) = *(b+i)+5;
}
Correct Answer
D. 2, 15, 6, 8, 10
Explanation
*(b+1) = *(b+i)+5;
1. i = 0 => *(b+1) ie 4 is replaced by *(b+0)+5 ie 2+5
2. i = 1 => *(b+1) ie 4 is replaced by *(b+1)+5 ie 4+5
3. i = 2 => *(b+1) ie 4 is replaced by *(b+2)+5 ie 6+5
4. i = 3 => *(b+1) ie 4 is replaced by *(b+3)+5 ie 8+5
5. i = 4 => *(b+1) ie 4 is replaced by *(b+4)+5 ie 10+5
5.
What will be the output of the program ?
int main()
{
char *str;
str = "%s";
printf(str, "K\n");
return 0;
}
Correct Answer
B. K
Explanation
printf(str, "K\n"); is replaced with printf("%s" , "K\n");
(since str = "%s";)
So it will print K.
6.
Which of the following function is used to find the first occurrence of a given string in another string?
Correct Answer
C. Strstr()
Explanation
The function strstr() is used to find the first occurrence of a given string in another string. It searches for the first occurrence of the specified substring within a larger string and returns a pointer to the first character of the found substring. This function is commonly used in string manipulation and searching operations.
7.
What will be the output of the program ?
int main()
{
char p[] = "%d\n";
p[1] = 'c';
printf(p, 65);
return 0;
}
Correct Answer
B. A
Explanation
In this program, the character array p initially contains the format specifier "%d\n". Then, the character at index 1 of the array p is changed to 'c', so the array becomes "%c\n", indicating that it will print a character.
When printf(p, 65) is executed, it interprets the format specifier as "%c\n", so it expects a character argument. The integer value 65 is interpreted as the ASCII code for the character 'A'. Therefore, the output of the program will be:
A
8.
Trace the output.
int main()
{
char str[] = "basic";
char *s = str;
printf("%s ", s++ +3);
printf("%s",s);
return 0;
}
Correct Answer
B. Ic asic
Explanation
printf("%s ", s++ +3); -> ic since (s++ +3) and s++ is post increment but +3 just print string from 'i'. It ll not increment the pointer to 3. printf("%s",s); here after incrementing (s++) It ll print ''asic''.
9.
What would be the equivalent pointer expression for referring the array element a[i][j][k][l]
Correct Answer
C. *(*(*(*(a+i)+j)+k)+l)
Explanation
The correct answer is *(*(*(*(a+i)+j)+k)+l). This expression is equivalent to referring to the array element a[i][j][k][l]. The expression starts with (a+i) which accesses the i-th element of the array a. Then, *(a+i) gives the pointer to the i-th element. Next, *(a+i)+j accesses the j-th element of the i-th element. This process continues with the addition of k and l, accessing the k-th and l-th elements respectively. Finally, the expression *(*(*(*(a+i)+j)+k)+l) dereferences the pointer to obtain the value of the array element a[i][j][k][l].
10.
What will be the output of the program ?
int main()
{
int i;
char a[] = "\0";
if(printf("%s", a))
printf("The string is empty\n");
else
printf("The string is not empty\n");
return 0;
}
Correct Answer
B. The string is not empty
Explanation
The function printf() returns the number of characters printed on the console. char a[] = "\0"; The variable a is declared as an array of characters and it initialized with "\0". It denotes that the string is empty. if(printf("%s", a)) The printf() statement does not print anything, so it returns '0'(zero). Hence the if the condition is failed. In the else part it prints "The string is not empty".
11.
Are the expression *ptr++ and ++*ptr are same?
Correct Answer
B. False
Explanation
*ptr++ increments the pointer and not the value,
++*ptr increments the value being pointed by ptr .
12.
If the size of integer is 4bytes, What will be the output of the program?
int main()
{
int arr[] = {12, 13, 14, 15, 16};
printf("%d, %d, %d\n", sizeof(arr), sizeof(*arr), sizeof(arr[0]));
return 0;
}
Correct Answer
C. 20, 4, 4
Explanation
The output of the program will be "20, 4, 4". The sizeof(arr) will give the total size of the array which is 20 bytes (5 integers, each taking 4 bytes). The sizeof(*arr) will give the size of the first element of the array, which is an integer and takes 4 bytes. The sizeof(arr[0]) will give the size of a single element in the array, which is also an integer and takes 4 bytes.
13.
What will be the output of the program ?
int main()
{
char str[] = "India\0\is Best\0";
printf("%d\n", strlen(str));
return 0;
}
Correct Answer
C. 5
Explanation
The function strlen returns the number of characters in the given string. Therefore, strlen(str) becomes strlen("India") contains 5 characters. A string is a collection of characters terminated by '\0'. The output of the program is "5"
14.
What will be the output of the program ?
int main()
{
printf(5+"Good Morning\n");
return 0;
}
Correct Answer
B. Morning
Explanation
printf(5+"Good Morning\n"); It skips the 5 characters and prints the given string.
Hence the output is "Morning"
15.
What will be the output of the program ?
int main()
{
char str1[] = "Hello";
char str2[] = "Hello";
if(str1 == str2)
printf("Equal\n");
else
printf("Unequal\n");
return 0;
}
Correct Answer
C. Unequal
Explanation
if(str1 == str2) here the address of str1 and str2 are compared. The addresses of both variables are not the same. Hence the if the condition is failed. At the else part it prints "Unequal".