Lesson1

Question 1

What is an array in C?

Answer 1

A collection of similar type of data items stored at contiguous memory locations

Question 2

How do you declare an array in C?

Answer 2

data_type array_name[array_size];

Question 3

What is the syntax for initializing an array during declaration?

Answer 3

data_type array_name[size] = {value1, value2, …, valueN};

Question 4

What is the starting index for arrays in C?

Answer 4

0

Question 5

What function is used to find the length of a string in C?

Answer 5

strlen

Question 6

What is the purpose of pointers in C?

Answer 6

To store the address of another variable

Question 7

True or False: An array can only store primitive data types.

Answer 7

True

Question 8

Fill in the blank: An array is the simplest _______ structure in C.

Answer 8

data

Question 9

What is the syntax for accessing an element in an array?

Answer 9

array_name[index];

Question 10

What are the two types of arrays mentioned?

Answer 10

• One-dimensional arrays
• Two-dimensional arrays

Question 11

How do you initialize an array using index?

Answer 11

By assigning values to each index individually, e.g., Arr[0]=value;

Question 12

What is a two-dimensional array?

Answer 12

An array of one-dimensional arrays, visualized as a table with rows and columns

Question 13

What is the output of accessing arr[1][0] in a 2D array defined as int arr[2][3] = { {1, 4, 2}, {3, 6, 8} };?

Answer 13

3

Question 14

What is the purpose of the ‘sizeof’ operator in the context of arrays?

Answer 14

To determine the size of the array in bytes

Question 15

What does the term ‘self-referential structure’ refer to?

Answer 15

A structure that contains a pointer to its own type

Question 16

True or False: You can use pointers to access elements of an array.

Answer 16

True

Question 17

How do you read values into an array in C?

Answer 17

Using a loop and scanf to input each value

Question 18

What is the output of the following code snippet? int marks[5] = {80, 60, 70, 85, 75}; printf(‘%d’, marks[2]);

Answer 18

70

Question 19

How do you find the sum of elements in an array?

Answer 19

Using a loop to iterate through the array and accumulate the sum

Question 20

What is the formula to calculate the average of an array?

Answer 20

average = sum / number_of_elements

Question 21

What is the syntax for defining a structure in C?

Answer 21

struct structure_name { data_type member1; data_type member2; … };

Question 22

What is an example of a basic string function in C?

Answer 22

• strcat
• strcpy
• strstr

Question 23

Fill in the blank: A _______ can store multiple values in a single variable.

Answer 23

array

Question 24

What does ‘union’ in C allow you to do?

Answer 24

Store different data types in the same memory location

Question 25

What is the maximum number of dimensions an array can have in C?

Answer 25

Theoretically, it can be up to 255 dimensions

Question 26

What does the term 'enumeration data type' refer to?

Answer 26

A user-defined type consisting of a set of named integer constants

Question 27

How is memory allocated for an array in C?

Answer 27

The compiler allocates a block of memory based on the array's size upon declaration

Question 28

True or False: Arrays in C can only hold integers.

Answer 28

False

Question 29

What is the output of the following code snippet? printf('%d', marks[5]); where marks is defined as int marks[5];

Answer 29

Undefined behavior (out of bounds access)

Question 30

How do you sort an array in C?

Answer 30

Using a sorting algorithm like bubble sort, quicksort, etc.

Question 31

What are the two main operations performed on arrays?

Answer 31

* Accessing elements * Modifying elements

Question 32

What is the significance of the index in an array?

Answer 32

It determines the position of an element within the array

Question 33

What is the syntax to declare a two-dimensional array?

Answer 33

data_type array_name[rows][columns];

Question 34

What is a string in C?

Answer 34

A one-dimensional array of characters terminated by a null character ('\0') ## Footnote The null character is crucial for identifying the end of the string.

Question 35

What differentiates a character array from a C string?

Answer 35

A C string is terminated with a unique character '\0' ## Footnote This termination character allows the program to determine where the string ends.

Question 36

What is the syntax for declaring a C string?

Answer 36

char string_name[size];

Question 37

How is a string literal declared in C?

Answer 37

char ch2[11] = 'javatpoint'; ## Footnote The compiler automatically adds the '\0' character.

Question 38

What does the strlen() function do?

Answer 38

Calculates the length of a given string excluding the null character.

Question 39

What is the purpose of the strcpy() function?

Answer 39

Copies the contents of the source string to the destination string.

Question 40

What does the strcat() function do?

Answer 40

Concatenates or joins the first string with the second string.

Question 41

What does the strcmp() function return?

Answer 41

Returns 0 if both strings are equal.

Question 42

What is the structure in C?

Answer 42

A user-defined data type that groups related variables of possibly different types into a single type.

Question 43

What keyword is used to define a structure in C?

Answer 43

struct

Question 44

What is the difference between an array and a structure?

Answer 44

An array is a homogeneous collection of similar types, while a structure can have elements of different types.

Question 45

What does the following code do? char arr[3][10] = {"Geek", "Geeks", "Geekfor"};

Answer 45

Defines an array of strings, where each string can hold up to 9 characters plus the null terminator.

Question 46

What is the output of the printf statement printing a string array?

Answer 46

Prints each string stored in the array, one per line.

Question 47

Fill in the blank: In C, an array of strings is a _______ array of character types.

Answer 47

two-dimensional

Question 48

What is the significance of the null character ('\0') in strings?

Answer 48

Indicates the termination of the string.

Question 49

How do you read a string input from the keyboard in C?

Answer 49

Using scanf("%s", str);

Question 50

What will the following code print? char str[] = "GeeksforGeeks"; length = strlen(str);

Answer 50

Length of the string, which is 13.

Question 51

True or False: The strcpy() function can copy one string to another of different sizes.

Answer 51

False ## Footnote The destination must be large enough to hold the copied string.

Question 52

What is the output of the following code? printf("%d\n", strcmp("Hello", "Hello"));

Answer 52

0

Question 53

What is the purpose of the printf function in C?

Answer 53

To output formatted text to the console.

Question 54

What is the maximum number of string values that can be stored in a string array declared as char variable_name[r][m]?

Answer 54

r

Question 55

What is the maximum number of character values that can be stored in each string array declared as char variable_name[r][m]?

Answer 55

m

Question 56

What is the main difference between an array and a structure in C?

Answer 56

An array is a homogenous collection of similar types, while a structure can have elements of different types.

Question 57

How do you declare a structure in C?

Answer 57

Using the struct keyword followed by the structure name and member variables with their data types.

Question 58

What is the syntax for declaring a structure in C?

Answer 58

struct structure_name { data_type member_name1; data_type member_name2; ... };

Question 59

What is a structure template in C?

Answer 59

The syntax used to declare a structure without allocating memory.

Question 60

Provide an example of a structure declaration for a Book.

Answer 60

struct book { char title[50]; char author[50]; double price; int pages; };

Question 61

How do you create an instance of a structure in C?

Answer 61

By defining variables of the structure type.

Question 62

What are the two methods to define structure variables?

Answer 62

* Structure Variable Declaration with Structure * Structure Variable Declaration after Structure definition

Question 63

How do you access members of a structure?

Answer 63

Using the dot operator (.) or the structure pointer operator (->).

Question 64

What is the output of printf when accessing structure members?

Answer 64

It displays the values of the structure's members.

Question 65

What is an array of structures in C?

Answer 65

A collection of multiple structure variables where each variable contains information about different entities.

Question 66

How do you define an array of structures?

Answer 66

struct book b[3] = { {"Learn C", 650.50, 325}, {"C Pointers", 175, 225}, {"C Pearls", 250, 250} };

Question 67

What is a union in C?

Answer 67

A user-defined data type that can contain elements of different data types, but only one member can store data at a time.

Question 68

What is the main advantage of using unions?

Answer 68

Unions provide an efficient way of using the same memory location for multiple purposes.

Question 69

What is the syntax for defining a union?

Answer 69

union union_name { datatype member1; datatype member2; ... };

Question 70

How do you initialize a union member?

Answer 70

By assigning a value to the member directly after declaring a union variable.

Question 71

What is a pointer in C?

Answer 71

A derived data type that can store the address of other C variables or a memory location.

Question 72

What is the syntax for declaring a pointer?

Answer 72

datatype *ptr;

Question 73

How do you assign an address to a pointer?

Answer 73

ptr = &var; where var is a variable.

Question 74

What operator is used to dereference a pointer?

Answer 74

The asterisk (*) operator.

Question 75

What happens when you change the value of a pointer's location?

Answer 75

It updates the value of the variable that the pointer is pointing to.

Question 76

What is the output of a program that prints the size of a structure?

Answer 76

It displays the total size in bytes of the structure.

Question 77

Fill in the blank: An array of structures in C can be defined as the collection of multiple _______.

Answer 77

structure variables

Question 78

What is the data type of the variable 'x' in the code?

Answer 78

int

Question 79

What is the data type of the variable 'y' in the code?

Answer 79

float

Question 80

What is the data type of the variable 'z' in the code?

Answer 80

char

Question 81

How is the pointer 'ptr_x' initialized?

Answer 81

ptr_x = &x

Question 82

What type of pointer is 'ptr_y'?

Answer 82

float *

Question 83

What does 'ptr_z' point to?

Answer 83

char

Question 84

What is the output format specifier for an integer in printf?

Answer 84

%d

Question 85

What is the output format specifier for a float in printf?

Answer 85

%f

Question 86

What is the output format specifier for a char in printf?

Answer 86

%c

Question 87

What is the output of 'printf("Value of x = %d\n", *ptr_x);'

Answer 87

Value of x = 10

Question 88

What is the output of 'printf("Value of y = %f\n", *ptr_y);'

Answer 88

Value of y = 1.300000

Question 89

What is the output of 'printf("Value of z = %c\n", *ptr_z);'

Answer 89

Value of z = p

Question 90

Fill in the blank: The pointer 'ptr_x' is of type _______.

Answer 90

int *

Question 91

True or False: The value of 'y' is printed as 1.3.

Answer 91

False

Question 92

What does the '*' operator do when used with a pointer?

Answer 92

Dereferences the pointer