Python Coding challenge - Day 843| What is the output of the following Python Code?

 

Code Explanation:

1. Defining the Class

class A:

A new class named A is created.

This acts as a blueprint for creating objects (instances).

2. Declaring a Class Variable

count = 0

count is a class variable, shared by all objects of class A.

It belongs to the class itself, not to individual instances.

Initially, A.count = 0.

3. Defining the Constructor

def __init__(self):

    A.count += 1

__init__ is the constructor, called automatically every time an object of class A is created.

Each time an object is created, this line increases A.count by 1.

So it counts how many objects have been created.

4. Loop to Create Multiple Objects

for i in range(3):

    a = A()

The loop runs 3 times (i = 0, 1, 2).

Each time, a new object a of class A is created, and the constructor runs.

Let’s trace it:

Iteration Action A.count value

1st (i=0) new A() created 1

2nd (i=1) new A() created 2

3rd (i=2) new A() created 3

After the loop ends, A.count = 3.

The variable a refers to the last object created in the loop.

5. Printing the Count

print(a.count)

Here, we access count through the instance a, but since count is a class variable, Python looks it up in the class (A.count).

The value is 3.

Final Output

3

500 Days Python Coding Challenges with Explanation