Curriculum
Course: Grade XI Computer Science
Login

Curriculum

Grade XI Computer Science

Lessons

0/11

Notes

0/11

Work Sheets

0/11
Text lesson

Le-7 Functions

School Revise · Class 11 Computer Science · Chapter 7

Functions

Code 083, Class 11. A function is a named block of code we can reuse. Here we define our own functions, pass values to them, return results and understand scope.

def

defines a function

2

built-in and user made

What this chapter is about

A function is a named block of code that does one job. We call it by its name whenever we need it, which saves repeating code and keeps programs tidy.

1. Defining and calling

We define a function with def, give it parameters in brackets, and use return to send a result back. We call it by writing its name with values (arguments).

def add(a, b): return a + b print(add(5, 3)) Output: 8

2. Default and positional arguments

Positional arguments are matched by order. A default argument has a value ready, so it may be left out when calling.

3. Scope, built-in and user-defined

A variable made inside a function is local and cannot be seen outside. A variable outside is global. Python has built-in functions like print() and len(), and the ones we write are user-defined.

Practise with the interactive

Build a small function, set its arguments, and see the value it returns. The interactive opens right here in the lesson.

Try it in the code lab

Write and run real Python right here in the lesson, then work through the practice problems with answers.

Starting Python...


Coding practice problems, with answers


Type each one into the code lab above, then open the card to see the worked solution and its output.



Problem 1. Write a function that adds two numbers.



SOLUTION


def add(a, b): return a + b print(add(5, 3))


OUTPUT


8







Problem 2. Write a function for the area of a rectangle.



SOLUTION


def area(l, b): return l * b print(area(8, 5))


OUTPUT


40







Problem 3. Write a function that returns the larger of two numbers.



SOLUTION


def bigger(a, b): if a > b: return a return b print(bigger(5, 9))


OUTPUT


9







Problem 4. Write a function that checks whether a number is even.



SOLUTION


def is_even(n): return n % 2 == 0 print(is_even(8))


OUTPUT


True







Problem 5. Write a greet function with a default name.



SOLUTION


def greet(name=”student”): print(“Hello,”, name) greet() greet(“Ravi”)


OUTPUT


Hello, student Hello, Ravi







Problem 6. Write a function to find a factorial.



SOLUTION


def fact(n): f = 1 for i in range(1, n + 1): f = f * i return f print(fact(5))


OUTPUT


120







Problem 7. Write a function that returns the square of a number.



SOLUTION


def square(x): return x * x print(square(6))


OUTPUT


36







Problem 8. Write a function that prints a times table.



SOLUTION


def table(n): for i in range(1, 4): print(n, “x”, i, “=”, n * i) table(2)


OUTPUT


2 x 1 = 2 2 x 2 = 4 2 x 3 = 6







Problem 9. Show local and global scope.



SOLUTION


x = 10 def show(): x = 5 print(“inside”, x) show() print(“outside”, x)


OUTPUT


inside 5 outside 10







Problem 10. Write a function that returns the sum of a list.



SOLUTION


def total(nums): return sum(nums) print(total([2, 4, 6]))


OUTPUT


12






Practice set A, multiple choice



1. Which keyword defines a function?



def.







2. Which keyword sends a value back from a function?



return.







3. A variable made inside a function is …



local, and cannot be seen outside.







4. print() and len() are examples of …



built-in functions.






Quick summary








A function is a named, reusable block of code. We define it with def, pass values as arguments (matched by position or given as defaults), and use return to send a result back. Variables made inside are local; those outside are global. print() and len() are built-in functions, and the ones we write are user-defined.












Open the Virtual Lab








These free Class 11 Computer Science notes explain functions, defining and calling, parameters and arguments, return values, default arguments, local and global scope with worked Python programs and practice, for CBSE students across India and the Gulf including the UAE, Saudi Arabia, Qatar, Oman, Kuwait and Bahrain.






© 2026 School Revise. All rights reserved. Original content aligned to the CBSE and NCERT Class 11 Computer Science syllabus. Unauthorised copying is not permitted.





	

	
	


	

		

					

			



		

			

	

	

		

			

				

		

	






	

		Layer 1	


	
	

		
			Login		
		Categories
	





	

			

							

	
		Mathematics	
	
	
							

	
		Science	
	
	
					

	








    
    			
			



  

    Privacy Policy
    Refund Policy
    Disclaimer
    Terms & Conditions
    Contact Us