O level programming

Question 1

What is a variable in programming?

Answer 1

A variable is a named storage location in memory that holds a value.

Question 2

What is the purpose of a loop in programming?

Answer 2

A loop is used to repeat a block of code until a certain condition is met.

Question 3

What is an algorithm?

Answer 3

An algorithm is a step-by-step procedure or formula for solving a problem.

Question 4

What is the difference between a compiler and an interpreter?

Answer 4

A compiler translates the entire source code into machine code before execution, while an interpreter translates and executes the code line by line.

Question 5

What is a function in programming?

Answer 5

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

Question 6

What is a conditional statement in programming?

Answer 6

A conditional statement is a control structure that executes different actions based on whether a condition is true or false.

Question 7

What is the purpose of an array in programming?

Answer 7

An array is used to store multiple values of the same data type under a single name.

Question 8

What does the term ‘syntax error’ refer to in programming?

Answer 8

A syntax error is a type of error that occurs when the rules of a programming language are not followed.

Question 9

What is a data type in programming?

Answer 9

A data type is a classification of data that specifies which operations can be performed on it.

Question 10

What is the purpose of a comment in programming?

Answer 10

A comment is used to add notes or explanations to code for documentation purposes and is ignored by the compiler or interpreter.

Question 11

What is the difference between local and global variables?

Answer 11

Local variables are declared within a specific block of code and can only be accessed within that block, while global variables are declared outside of any block and can be accessed throughout the program.

Question 12

What is the purpose of a switch statement in programming?

Answer 12

A switch statement is used to execute different blocks of code based on the value of an expression.

Question 13

What is the difference between ‘==’ and ‘=’ in programming?

Answer 13

’==’ is used to compare two values for equality, while ‘=’ is used to assign a value to a variable.

Question 14

What is a pointer in programming?

Answer 14

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

Question 15

What is the purpose of a while loop in programming?

Answer 15

A while loop is used to repeatedly execute a block of code as long as a specified condition is true.

Question 16

What is the difference between ‘&&’ and ‘||’ in programming?

Answer 16

‘&&’ is the logical AND operator that returns true if both conditions are true, while ‘||’ is the logical OR operator that returns true if at least one condition is true.

Question 17

What is the purpose of a for loop in programming?

Answer 17

A for loop is used to iterate over a sequence of values for a specified number of times.

Question 18

What is the purpose of a break statement in programming?

Answer 18

A break statement is used to exit a loop or switch statement prematurely.

Question 19

What is the purpose of a continue statement in programming?

Answer 19

A continue statement is used to skip the current iteration of a loop and proceed to the next iteration.

Question 20

What is a constant in programming?

Answer 20

A constant is a value that cannot be altered or modified during program execution.

Question 21

What is the purpose of a do-while loop in programming?

Answer 21

A do-while loop is used to execute a block of code at least once, then repeatedly execute it based on a specified condition.

Question 22

What is the purpose of a function prototype in programming?

Answer 22

A function prototype declares the function’s name, return type, and parameters before the actual function definition.

Question 23

What is recursion in programming?

Answer 23

Recursion is a technique where a function calls itself to solve a smaller instance of the same problem.

Question 24

What is a two-dimensional array in programming?

Answer 24

A two-dimensional array is an array of arrays, where each element is itself an array.

Question 25

What is the purpose of the 'return' statement in a function?

Answer 25

The 'return' statement is used to exit a function and return a value to the calling code.

Question 26

What is a structure in programming?

Answer 26

A structure is a user-defined data type that groups related data items of different data types.

Question 27

What is the purpose of a header file in programming?

Answer 27

A header file contains declarations of functions, variables, and constants that can be shared across multiple source files.

Question 28

What is the difference between stack and heap memory?

Answer 28

Stack memory is used for static memory allocation and is managed by the compiler, while heap memory is used for dynamic memory allocation and must be managed by the programmer.

Question 29

What is the purpose of the 'sizeof' operator in programming?

Answer 29

The 'sizeof' operator returns the size in bytes of a data type or a variable.

Question 30

What is the purpose of a typedef in programming?

Answer 30

A typedef creates an alias for an existing data type to make code more readable and maintainable.

Question 31

What is the purpose of a static variable in programming?

Answer 31

A static variable retains its value between function calls and is initialized only once.

Question 32

What is the purpose of the 'extern' keyword in programming?

Answer 32

The 'extern' keyword is used to declare a variable or function that is defined in another source file.

Question 33

What is the purpose of the 'const' keyword in programming?

Answer 33

The 'const' keyword is used to declare a variable as read-only, meaning its value cannot be changed.

Question 34

What is a bitwise operator in programming?

Answer 34

A bitwise operator performs operations on individual bits of binary numbers.

Question 35

What is the purpose of the 'union' keyword in programming?

Answer 35

The 'union' keyword is used to define a data structure that can hold different data types in the same memory location.

Question 36

What is the purpose of the 'enum' keyword in programming?

Answer 36

The 'enum' keyword is used to define a set of named integer constants.

Question 37

What is the purpose of the 'continue' statement in programming?

Answer 37

The 'continue' statement is used to skip the current iteration of a loop and proceed to the next iteration.

Question 38

What is the purpose of the 'break' statement in programming?

Answer 38

The 'break' statement is used to exit a loop or switch statement prematurely.

Question 39

What is the purpose of the 'auto' keyword in programming?

Answer 39

The 'auto' keyword is used to declare automatic variables that are automatically initialized to garbage values.

Question 40

What is the purpose of the 'register' keyword in programming?

Answer 40

The 'register' keyword is used to declare variables that are stored in CPU registers for faster access.