Untitled Deck

Question 1

Who developed the C programming language and when?

Answer 1

C was developed by Dennis Ritchie at Bell Labs in 1972.

Question 2

What is the main purpose of the C programming language?

Answer 2

C is a general-purpose, procedural programming language used for system programming, developing operating systems, and applications.

Question 3

What are the basic data types in C?

Answer 3

The basic data types are:
- int (integer)
- float (floating-point number)
- char (character)
- double (double-precision floating-point number).

Question 4

What is the role of the main() function in a C program?

Answer 4

The main() function is the entry point of every C program. The program execution starts from the main() function.

Question 5

What are comments in C, and how are they written?

Answer 5

Comments are used to make the code more readable and are ignored during execution.
- Single-line comment: // Comment here
- Multi-line comment: /* Comment here */.

Question 6

What are the different types of loops in C?

Answer 6

The types of loops are:
- for loop
- while loop
- do-while loop.

Question 7

What is the difference between break and continue?

Answer 7

• break: Terminates the loop or switch statement immediately.
• continue: Skips the rest of the current loop iteration and moves to the next iteration.

Question 8

What is a switch statement?

Answer 8

A switch statement is a control statement that executes a block of code based on the value of an expression, typically using case labels.

Question 9

What is the difference between if and else if?

Answer 9

• if evaluates a condition and executes a block if the condition is true.
• else if is used to test multiple conditions after an initial if.

Question 10

What is a function in C?

Answer 10

A function is a block of code that performs a specific task and can be reused.

Question 11

What are the types of functions in C?

Answer 11

1. Library functions: Predefined functions like printf() and scanf().
2. User-defined functions: Functions created by the programmer.

Question 12

What are function prototypes in C?

Answer 12

A function prototype declares the function name, return type, and parameters before its definition to inform the compiler about the function.

Question 13

What is recursion in C?

Answer 13

Recursion is when a function calls itself directly or indirectly to solve smaller instances of a problem.

Question 14

What is a pointer in C?

Answer 14

A pointer is a variable that stores the address of another variable.

Question 15

How do you declare a pointer in C?

Answer 15

A pointer is declared using the * symbol. Example: int *ptr;

Question 16

What is the difference between malloc() and calloc()?

Answer 16

• malloc(): Allocates a single block of memory of a specified size and doesn’t initialize it.
• calloc(): Allocates multiple blocks of memory and initializes them to zero.

Question 17

What is NULL in C?

Answer 17

NULL is a macro representing a null pointer, indicating that the pointer does not point to any valid memory location.

Question 18

How are arrays declared in C?

Answer 18

Arrays are declared as:
datatype array_name[size];
Example: int arr[5];

Question 19

What is the difference between a one-dimensional and a two-dimensional array?

Answer 19

• A one-dimensional array is a linear list of elements. Example: int arr[5];
• A two-dimensional array is a table of elements with rows and columns. Example: int arr[3][4];.

Question 20

How do you terminate a string in C?

Answer 20

Strings in C are terminated with the null character \0.

Question 21

What are the modes in file handling in C?

Answer 21

• “r”: Read mode
• “w”: Write mode
• “a”: Append mode
• “r+”: Read and write mode.

Question 22

What are the standard file I/O functions in C?

Answer 22

• fopen()
• fclose()
• fread()
• fwrite()
• fprintf()
• fscanf().

Question 23

What is the purpose of fclose()?

Answer 23

The fclose() function closes a file and frees associated resources.

Question 24

What is the difference between #define and const?

Answer 24

• #define: Preprocessor directive for defining constants or macros.
• const: Keyword to declare read-only variables.

Question 25

What is the purpose of the return statement?

Answer 25

The return statement ends a function and optionally returns a value to the calling function.

Question 26

What is the difference between struct and union?

Answer 26

• struct: Allocates memory for all members separately.
• union: Allocates shared memory for all members, equal to the largest member.