Python Coding challenge - Day 850| What is the output of the following Python Code?

 

Code Explanation:

1. Class Definition Begins

class Demo:

A new class named Demo is created.

This class will contain attributes and methods.

2. Class-Level Attribute

    nums = []

nums is a class variable (shared by all objects of the class).

It is an empty list [] initially.

Any object of Demo will use this same list unless overridden.

3. Method Definition

    def add(self, val):

        self.nums.append(val)

The method add() takes self (object) and a value val.

It appends val to self.nums.

Since nums is a class list, appending through any object affects the same list.

4. Creating First Object

d1 = Demo()

Creates object d1 of class Demo.

d1 does not have its own nums; it uses the shared class list.

5. Creating Second Object

d2 = Demo()

Creates another object d2.

d2 also uses the same class-level list nums as d1.

6. Adding a Number Using d1

d1.add(4)

Calls the add() method on d1.

This executes self.nums.append(4).

Since nums is shared, the list becomes:

[4]

7. Printing Length of nums from d2

print(len(d2.nums))

d2 looks at the same shared list.

That list contains one element: 4

So length is:

1

Final Output:

1

400 Days Python Coding Challenges with Explanation