Functions

Question 1

What is a function in C?

Answer 1

A named, independent section of C code that performs a specific task and optionally returns a value to the calling statement.

Question 2

What are the two types of functions in C?

Answer 2

• Standard Library functions (built-in)
• User-defined functions (custom)

Question 3

What is the syntax for creating a function in C?

Answer 3

[data_type] function_name([data_type param,…]){ data_type local_variable; … program_statement; … [return expression;]}

Question 4

What does the function prototype declaration tell the compiler?

Answer 4

• Its data type
• Its name
• The argument it takes
• Who can call it

Question 5

What keyword is used to return a value from a function?

Answer 5

return

Question 6

What is the default data type of a function if omitted?

Answer 6

int

Question 7

What does ‘call by value’ mean?

Answer 7

Each argument passed to a function is evaluated, and its value is passed into the function.

Question 8

What is ‘call by reference’?

Answer 8

A method where a reference to the variable (memory address) is passed into the function instead of its value.

Question 9

What are non-returning functions without parameters?

Answer 9

Functions declared as void that do not return a value and do not take any parameters.

Question 10

What is a returning function with parameters?

Answer 10

A function that returns a value and accepts parameters.

Question 11

Fill in the blank: The function’s _______ is a unique identifier used to call it.

Answer 11

name

Question 12

What is the purpose of the standard library functions in C?

Answer 12

They are built-in functions defined in header files.

Question 13

True or False: A function can be called from within another function.

Answer 13

True

Question 14

What is the role of the return statement in a function?

Answer 14

It indicates that the function is to return the value of the expression back to the calling function.

Question 15

What must the function prototype declaration reflect?

Answer 15

The data type of the return value.

Question 16

What does the function ‘double_it’ do in the provided example?

Answer 16

It doubles the input value a specified number of times and prints the result.

Question 17

What is a user-defined function?

Answer 17

A function created by the user to meet specific needs in the program.

Question 18

What is the syntax for non-returning functions with parameters?

Answer 18

void function_name(data_type param1,…){ statement1; statement2; … }

Question 19

What is the output of the function ‘hello_world’ that accepts an integer parameter?

Answer 19

It prints ‘Hello World!’ and the value of the parameter.

Question 20

What is the significance of the ‘&’ symbol in a function call?

Answer 20

It is used to pass the address of a variable (for call by reference).

Question 21

What happens when a function is called with parameters that are not the same name as the corresponding parameters?

Answer 21

It is valid, as it is the variable’s value that is being passed, not its name.

Question 22

What is the result of the function ‘divide’ in the example?

Answer 22

It returns the result of dividing two integers as a float.

Question 23

What is the syntax for a returning function without parameters?

Answer 23

data_type function_name() { statement1; statement2; return expression; }

Question 24

What is the purpose of the function getInteger()?

Answer 24

To prompt the user for an integer value and return it.

Question 25

What is the output when the user enters the integer value 4 in the getInteger() function?

Answer 25

The value of number is 4

Question 26

What is the syntax for a returning function with parameters?

Answer 26

data_type function_name(data_type param1,…) { statement1; statement2; return expression; }

Question 27

What does the computeAverage function do?

Answer 27

Calculates the average of three grades (math, science, english).

Question 28

What is the output of the computeAverage function when grades are 90, 85, and 98?

Answer 28

Average grade is 91.00

Question 29

What is the scope of function variables?

Answer 29

Local variables can only be accessed within the function where they are defined.

Question 30

In the inner block of a function, how is a variable name treated if redefined?

Answer 30

The inner block variable hides the outer block variable.

Question 31

What is the output of the outer block’s variable a if it is defined as 1 and inner block redefines it as 5?

Answer 31

outer block a: 1

Question 32

True or False: A function’s local variables can be accessed by other functions.

Answer 32

False

Question 33

What are local variables also referred to as?

Answer 33

Internal variables

Question 34

What are global variables?

Answer 34

Variables declared outside of any function block, accessible by any function.

Question 35

What is the output of the global variable a if it is defined as 3?

Answer 35

main a: 3

Question 36

What is recursion in programming?

Answer 36

The process of calling a function within itself.

Question 37

What is an advantage of using recursion over iterative statements?

Answer 37

The code stays simpler and shorter.

Question 38

What is the output of the sumOf function when called with the value 5?

Answer 38

Result: 15

Question 39

Fill in the blank: The process of calling a function inside the same function is called ______.

Answer 39

recursion

Question 40

What caution should be taken when using recursion?

Answer 40

It can lead to a program that never terminates.