Python Coding challenge - Day 724| What is the output of the following Python Code?

 

Code Explanation:

1) class A:

Starts the class definition for a class named A.

Everything indented under this line is inside the class body.

2) count = 0

Declares a class variable count and sets it to 0.

This variable belongs to the class object A and is shared by all instances (unless an instance creates its own count attribute later).

3) def __init__(self):

Defines the constructor (initializer) for A.

This method runs automatically every time you create a new A() instance.

4) A.count += 1

Inside __init__, this line increments the class variable count by 1.

Using A.count explicitly updates the variable on the class A, not an instance attribute.

So each time any A() is constructed, the shared A.count increases.

5) a1 = A()

Creates the first instance of A.

__init__ runs → A.count goes from 0 to 1.

6) a2 = A()

Creates the second instance.

__init__ runs → A.count goes from 1 to 2.

7) a3 = A()

Creates the third instance.

__init__ runs → A.count goes from 2 to 3.

8) print(a1.count, A.count)

a1.count looks for an instance attribute count on a1. None exists, so Python falls back to the class attribute A.count, which is 3.

A.count directly accesses the class variable count, also 3.

So both values printed are the same.

Final Output

3 3

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