C Programming Multiple Choice Question - Array And String
This section focuses on the "Array And String" of the C programming. These Multiple Choice Questions (mcq) should be practiced to improve the C programming skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
1. What is the maximun number of dimensions an array in C may have?
A. Two
B. eight
C. sixteen
D. Theoratically no limit. The only practical limits are memory size and compilers
View Answer
Ans : D
Explanation: The maximum size of an array is determined by the amount of memory that a program can access. On a 32-bit system, the maximum amount of memory that can be addressed by a pointer is 2^32 bytes which is 4 gigabytes. The actual limit may be less, depending on operating system implementation details.
2. A one dimensional array A has indices 1....75. Each element is a string and takes up three memory words. The array is stored at location 1120 decimal. The starting address of A[49] is
A. 1264
B. 1164
C. 1167
D. 1267
View Answer
Ans : A
Explanation: Start address of the element = base address of array + number of elements * size of each element = 1120 + 48 * 3 = 1264
3. What will be the address of the arr[2][3] if arr is a 2-D long array of 4 rows and 5 columns and starting address of the array is 2000?
A. 2048
B. 2056
C. 2052
D. 2042
View Answer
Ans : C
Explanation: 2000 + 4*(5*2) + 3*4 .
4. Array can be considered as set of elements stored in consecutive memory locations but having __________.
A. Same data type
B. Different data type
C. Same scope
D. None of these
View Answer
Ans : A
Explanation: Array store elements of same data type.
5. Array is an example of _______ type memory allocation.
A. Compile time
B. Run time
C. Both A and B
D. None of the above
View Answer
Ans : A
Explanation: Array allocate memory at compile time
6. Size of the array need not be specified, when
A. Initialization is a part of definition
B. It is a formal parameter
C. It is a declaratrion
D. All of the above
View Answer
Ans : A
Explanation: int arr[] = {1,2,3}; In this case size of array need not to be specified when initialization is a part of defination.
7. The information about an array used in program will be stored in
A. Symbol Table
B. Activation Record
C. Dope Vector
D. Both A and B
View Answer
Ans : C
Explanation: In computer programming, a dope vector is a data structure used to hold information about a data object, e.g. an array, especially its memory layout.
8. The parameter passing mechanism for an array is
A. call by value
B. call by reference
C. call by value-result
D. None of the above
View Answer
Ans : B
Explanation: The parameter passing mechanism for an array is call by reference.This technique uses in/out-mode semantics. Changes made to formal parameter do get transmitted back to the caller through parameter passing. Any changes to the formal parameter are reflected in the actual parameter in the calling environment as formal parameter receives a reference (or pointer) to the actual data.
9. A string that is a formal parameter can be declared
A. An array with empty braces
B. A pointer to character
C. Both A and B
D. None of the above
View Answer
Ans : C
Explanation: A string that is a formal parameter can be declared by both A and B.
10. Which of the following function is more appropriate for reading in a multi-word string?
A. scanf()
B. printf()
C. gets()
D. puts()
View Answer
Ans : C
Explanation: The C library function gets() reads a line from stdin and stores it into the string pointed to by str.
11. Length of the string "letsfindcourse" is
A. 13
B. 14
C. 15
D. 12
View Answer
Ans : B
Explanation: None
12. How will you print
on the screen?
A. printf("
");
B. printf('
');
C. printf("\n");
D. printf(""
")
View Answer
Ans : C
Explanation: The statement printf("\n"); prints '
' on the screen.
13. If the two strings are identical, then strcmp() function returns
A. -1
B. 1
C. 0
D. None
View Answer
Ans : C
Explanation: if both the strings are equal then strcmp return 0.
14. Which of the following statements are correct ?
1: A string is a collection of characters terminated by '.
2: The format specifier %s is used to print a string.
3: The length of the string can be obtained by strlen().
4: The pointer CANNOT work on string.
A. 1,2,3
B. 1,2
C. 2,4
D. 3,4
View Answer
Ans : A
Explanation: None
15. Let x be an array.Which of the following operations is illegal?
i) ++x.
ii) x+1.
iii) x++.
iv) x*2.
A. I and II
B. I, III and IV
C. III and IV
D. II and III
View Answer
Ans : D
Explanation: None
16. Strcat function adds null character
A. Only if there is space
B. Always
C. Depends on the standard
D. epends on the compiler
View Answer
Ans : B
Explanation: None
17. Which of the following function sets first n characters of a string to a given character?
A. strset()
B. strnset()
C. strcset()
D. strinit()
View Answer
Ans : B
Explanation: char *strnset(char *s, int ch, size_t n); Sets the first n characters of s to ch
18. The library function used to find the last occurrence of a character in a string is
A. strnstr()
B. laststr()
C. strrchr()
D. strstr()
View Answer
Ans : C
Explanation: char *strrchr(const char *s, int c);
It scans a string s in the reverse direction, looking for a specific character c.
19. Which of the following gives the memory address of the first element in array foo, an array with 10 elements?
A. foo
B. &foo
C. foo[0]
D. &foo[0]
View Answer
Ans : A
Explanation: name of array give the base address of array which is the address of first element of array.
20. What will happen if in a C program you assign a value to an array element whose subscript exceeds the size of array?
A. The element will be set to 0.
B. The compiler would report an error.
C. The program may crash
D. None of the above
View Answer
Ans : C
Explanation: None
21. An array elements are always stored in ________ memory locations.?
A. Sequential
B. Random
C. Sequential and Random
D. None of the above
View Answer
Ans : A
Explanation: None
22. Let x be an array. Which of the following operations are illegal?
I. ++x
II. x+1
III. x++
IV. x*2
A. I and II
B. I, II and III
C. II and III
D. I, III and IV
View Answer
Ans : D
Explanation: int x[10]; * x will store the base address of array. *Statement I, III and IV is invalid.
23. What is the output of this program?
void main()
{
int a[8] = {1,2,3,4,5};
printf("%d", a[5]);
}
A. 5
B. 6
C. 0
D. Garbage Value
View Answer
Ans : C
Explanation: When an array is partially initialized at the time of declaration then the remaining elements of the array is initialized to 0 by default.
24. What is the output of this program?
void main()
{
int arr[10];
printf("%d %d", arr[-2], arr[11]);
}
A. 0 0
B. Garbage value 0
C. Garbage value Garbage value
D. Compilation Error
View Answer
Ans : C
Explanation: In c compiler does not check array with its bounds, value at the computed location is displayed.
25. What will be the output of the program if the array begins at 1000 and each integer occupies 2 bytes?
void main()
{
int arr[2][2] = { 1, 2, 3, 4 };
printf("%u, %u", arr+1, &arr+1);
}
A. 1004 1008
B. 1002 1008
C. 1002 1002
D. 1008 1002
View Answer
Ans : A
Explanation: For a two-dimensional array like a reference to array has type "pointer to array of 2 ints". Therefore, arr+1 is pointing to the memory location of first element of the second row in array i.e 1000 + 2*2 = 1004. &arr has type "pointer to array of 2 arrays of 2 ints", totally 4 ints. Therefore, &a+1 denotes
1000 + 4*2 = 1008.
26. What is the output of this program?
#include <stdio.h>
int main()
{
int arr[5] = {1,2,3,4,5};
int p, q, r;
p = ++arr[1];
q = arr[1]++;
r = arr[p++];
printf("%d, %d, %d", p, q, r);
return 0;
}
A. 3 4 5
B. 3 4 4
C. 4 3 4
D. 4 4 5
View Answer
Ans : C
Explanation: p = ++arr[1] will becomes ++2 = 3. q = arr[1]++ becomes 3++ and finally arr[3++] = 4 .Due to p++ in statment arr[p++] value of p becomes 4.
27. What is the output of this program?
#include <stdio.h>
int main()
{
int a[1]={100};
printf("%d", 0[a]);
return 0;
}
A. 100
B. 0
C. Garbage Value
D. Compilation Error
View Answer
Ans : A
Explanation: a[0] can be written as 0[a]
28. What is the output of this program? (Assume that base address of a is 1000 and size of integer is 32 bit)
int main()
{
int a[10];
a++;
printf("%u", a);
return 0;
}
A. 1004
B. 1002
C. 1008
D. Lvalue Required
View Answer
Ans : D
Explanation: Array name in C is implemented by a constant pointer. It is not possible to apply increment and decrement on constant types.
29. Which of the following will print the value 2 for the above code?
#include <stdio.h>
int main()
{
int arr[10][20][30] = {0};
arr[3][2][1] = 2;
return 0;
}
A. printf("%d",*(((a+3)+2)+1));
B. printf("%d",***((a+3)+2)+1);
C. printf("%d",*(*(*(a+3)+2)+1));
D. None of the above
View Answer
Ans : C
Explanation: None
30. Which is true about the given statment ?
int arr[10] = {0,1,2,[7]=7,8,9};
A. Compipation Error
B. Run-time Error
C. This is allowed in C
D. None of the above
View Answer
Ans : C
Explanation: In C, initialization of array can be done for selected elements as well.
31. What is the output of this program?
#include <stdio.h>
void main(){
char c[] = "GATE2011";
char *p =c;
printf("%s", p + p[3] - p[1]);
}
A. GATE2011
B. E2011
C. 2011
D. 11
View Answer
Ans : C
Explanation: p[3] - p[1] = ASCII value of 'E' - ASCII value of 'A' = 4 . So the expression p + p[3] - p[1] becomes p + 4.
32. What is the output of this program?
#include <stdio.h>
#include<string.h>
void main()
{
char s1[20] = "Hello", s2[10] = " World";
printf("%s", strcpy(s2, strcat(s1, s2)));
}
A. Hello World
B. HelloWorld
C. Hello
D. World
View Answer
Ans : A
Explanation: strcat will concatenate the string s1 and s2 and copy it in s2.
33. How many times the loop will execute ?
#include <stdio.h>
int main()
{
char str[10] = "98765", *p;
p = str + 1;
*p = '0' ;
printf ("%s", str);
}
A. 98
B. 0
C. 98766
D. 90765
View Answer
Ans : D
Explanation: address of second character is stored in p and then its value is changed to 0 and hence 8 is replaced by 0.
34. What is the output of this program?
#include <stdio.h>
void main()
{
char s[] = "Letsfind course";
printf("%s", str);
}
A. Letsfindcourse
B. Letsfind
C. course
D. Compilation Error
View Answer
Ans : B
Explanation: String will be printed till it don't find the null character here null character is given after Letsfind. Therefore Letsfind will be printed
35. What is the output of this program?
#include
int main()
{
char str[14] = "Letsfindcourse";
printf("%s", str);
return 0;
}
A. Letsfindcours
B. Letsfindcourse
C. Run Time Error
D. Compilation Error
View Answer
Ans : A
Explanation: None
36. What is the output of the given code ?
#include <stdio.h>
int main()
{
int i;
char str[] = "";
if(printf("%s", str))
printf("Empty String");
else
printf("String is not empty");
return 0;
}
A. Empty String
B. String is not empty
C. 0
D. None of the above
View Answer
Ans : B
Explanation: printf does not print anything so it will return 0 and hence else part will execute.
37. What is the output of this program?
#include <stdio.h>
int main()
{
char str = "Hello";
printf("%s", str);
return 0;
}
A. Hello
B. Base address of str
C. Segmentation Fault
D. None of the above
View Answer
Ans : C
Explanation: None
38. What is the output of this program?
#include <stdio.h>
int main()
{
char s1[] = "Hello";
char s2[] = "Hello";
if(s1 == s2)
printf("Same");
else
printf("Not Same");
return 0;
}
A. Not Same
B. Same
C. Compilation Error
D. None of the above
View Answer
Ans : A
Explanation: The base address of s1 and s2 are checked which are not equal and hence else part will execute.
39. What will be the output of the program ?
#include <stdio.h>
int main(void)
{
char p;
char buf[10]={1,2,3,4,5,6,9,8};
p=(buf+1)[5];
printf("%d",p);
return 0;
}
A. 5
B. 6
C. 9
D. None of the above
View Answer
Ans : C
Explanation: x[i] is equivalent to *(x+i)
40. What will be the output of the program ?
#include <stdio.h>
int main()
{
int a[5]={5,1,15,20,25};
int i,j,m;
i = ++a[1];
j = a[1]++;
m = a[i++];
printf("%d, %d, %d", i, j, m);
return 0;
}
A. 3,2,15
B. 2,3,20
C. 2,1,15
D. 1.2.5
View Answer
Ans : A
Explanation: None
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