Arrays & Strings - Practice MCQs for CCAT

Correct Answer: D - Collection of same data types

An array stores multiple elements of the same data type in contiguous memory locations.

Correct Answer: A - Contiguously

Array elements occupy consecutive memory locations, which allows index-based access.

Correct Answer: B - 0

Uninitialized elements in a partially initialized array are set to 0.

Correct Answer: B - 0

In C, array indexing starts from 0.

Correct Answer: B - \0

Strings in C are null-terminated, meaning they end with the null character \0.

Correct Answer: B - 20

*(arr + 1) is equivalent to arr[1], which is 20. Adding 1 to the array pointer moves to the next element.

Correct Answer: B - int arr[3][4];

A 2D array is declared as data_type name[rows][columns]. So int arr[3][4] creates 3 rows and 4 columns.

Correct Answer: D - 5

strlen() returns the length of the string excluding the null terminator. "Hello" has 5 characters.

Correct Answer: C - 6

sizeof() includes the null terminator, so "Hello" occupies 6 bytes (5 characters + 1 null character).

Correct Answer: D - strcpy()

strcpy(dest, src) copies the source string to the destination string.

Correct Answer: A - Garbage value

arr[5] is out of bounds (valid indices are 0-4). Accessing it results in undefined behavior, typically a garbage value.

Correct Answer: A - Concatenates two strings

strcat(dest, src) appends the source string at the end of the destination string.

Correct Answer: B - W

str[0] accesses the first character of the string, which is "W".

Correct Answer: D - Negative value

strcmp() returns negative if first string is less than second. "abc" < "abd" because 'c' < 'd'.

Correct Answer: D - By passing the array name

When you pass the array name, you pass the base address (pointer to first element). Arrays decay to pointers when passed to functions.

Correct Answer: D - 0

str1 and str2 are different arrays at different memory locations. Comparing them compares addresses, not content, so result is 0 (false).

Correct Answer: B - 60

Total elements = 5 × 4 × 3 = 60. A 3D array with dimensions [5][4][3] can store 60 integers.

Correct Answer: A - Hello

printf with %s stops printing at the first null character (\0). So only "Hello" is printed.

Correct Answer: D - <string.h>

String manipulation functions are declared in <string.h> header file.

Correct Answer: D - 0 0

When an array is initialized with {0}, all elements are set to 0. So both arr[0] and arr[4] are 0.

Correct Answer: A - 40

*(arr + 3) accesses the element at index 3, which is 40. Pointer arithmetic adds 3 * sizeof(int) bytes to the base address.

Correct Answer: C - 6

sizeof(str) returns 6 because the string "Hello" has 5 characters plus the null terminator '\0', totaling 6 bytes.

Correct Answer: C - 0 0

When an array is partially initialized, the remaining elements are automatically initialized to 0. So a[3] and a[4] are both 0.

Correct Answer: C - 0

s1 and s2 are two different arrays stored at different memory locations. Comparing them with == compares their addresses, not their contents, so the result is 0.

Correct Answer: B - 5

strlen() counts characters until it encounters the first null terminator. It stops at '\0' after "Hello", returning 5.

Correct Answer: A - 4

arr[1][1] accesses row index 1, column index 1. Row 1 is {3,4}, so the element at column 1 is 4.

Correct Answer: B - strcat()

strcat() is the standard library function declared in <string.h> used to concatenate (append) one string to the end of another.

Correct Answer: C - CCAT2026

strcat() appends "2026" to the end of "CCAT", resulting in "CCAT2026". The buffer str[10] is large enough to hold the result.

Correct Answer: A - 10

p initially points to arr[0]. After p++, it points to arr[1] which is 10. Incrementing a pointer moves it by sizeof(int) bytes.

Correct Answer: B - Null character

The string "CDAC" has indices 0-3 for characters C, D, A, C. Index 4 contains the null terminator '\0'.

Correct Answer: C - Negative value

strcmp() compares strings lexicographically. Since 'a' (97) comes before 'b' (98) in ASCII, "apple" < "banana", so it returns a negative value.

Correct Answer: D - 6

*(arr+1) gives the pointer to the second row {4,5,6}. *(*(arr+1)+2) accesses the element at index 2 of the second row, which is 6.

Correct Answer: C - a

p points to 'E' at index 0. *(p+2) accesses index 2, which is 'a' in the string "Exam".

Correct Answer: D - char s[12] = "Programming";

"Programming" has 11 characters plus a null terminator, requiring at least 12 bytes. char s[12] is the minimum valid size. Single quotes in option D are invalid for strings.

Correct Answer: B - 3

In C, a[i] is equivalent to *(a+i), which is the same as *(i+a) or i[a]. So 2[a] is the same as a[2], which is 3.

Correct Answer: D - World

strcpy() copies the content of str2 into str1, replacing the original content. After the copy, str1 contains "World".

Correct Answer: B - 80

A 2D array int arr[5][4] has 5 × 4 = 20 elements. Each int is 4 bytes, so total size is 20 × 4 = 80 bytes.

Correct Answer: C - f

sizeof(s) is 7 (6 chars + null). s[7-2] = s[5] = 'f'. The last character before the null terminator.

Correct Answer: B - 20

p points to arr[2] (value 30). p[-1] is equivalent to *(p-1), which accesses arr[1], giving 20.

Correct Answer: A - Undefined behavior

String literals are stored in read-only memory. Attempting to modify them through a pointer leads to undefined behavior, which often causes a segmentation fault.

Correct Answer: D - Copies src and pads remaining with null characters

When the source string is shorter than n, strncpy() copies all characters from src and pads the rest of the n characters with null ('\0') characters.

Correct Answer: C - 6

Post-increment p++ returns the current value of p before incrementing. So *(p++) dereferences the original p pointing to a[0]=5, then adds 1, giving 6.

Correct Answer: A - void func(int arr[][3])

When passing a 2D array to a function, the first dimension can be omitted but all subsequent dimensions must be specified. void func(int arr[][3]) is correct.

Correct Answer: A - Exam

strchr() returns a pointer to the first occurrence of 'E' in the string. Printing from that pointer gives "Exam".

Correct Answer: C - 5

sizeof(arr) gives total bytes (20 on 4-byte int), sizeof(arr[0]) gives bytes per element (4). Dividing gives the number of elements: 20/4 = 5.

Correct Answer: A - 0

strcmp() returns 0 when both strings are identical. Since a and b both contain "xyz", the comparison returns 0.

Correct Answer: C - 9

The loop sets arr[i] = i*i. For i=3, arr[3] = 3*3 = 9.

Correct Answer: A - World

The first strtok() call returns "Hello". The second call with NULL continues tokenizing the same string, returning "World".

Correct Answer: C - 2

Pointer subtraction gives the number of elements between two pointers, not the byte difference. &arr[2] - &arr[0] = 2 elements.

Correct Answer: A - 3+4=7

sprintf() works like printf() but writes the formatted output to a string buffer instead of stdout. It formats the integers into the string "3+4=7".