Python Coding Challange - Question With Answer(01130225)

 

Explanation of print(0.1 + 0.2 == 0.3)

In Python, floating-point numbers are represented using binary (base-2) approximation, which can introduce small precision errors.

Step-by-Step Breakdown:

1. Addition Operation (0.1 + 0.2)

   • In decimal (base-10), 0.1 + 0.2 should be exactly 0.3.
   • However, in binary (base-2), 0.1 and 0.2 have infinite repeating representations, leading to a small rounding error.
   • The actual result stored in memory is slightly greater than 0.3 (approximately 0.30000000000000004).

2. Comparison (== 0.3)

   • Since 0.1 + 0.2 evaluates to 0.30000000000000004, the equality check 0.1 + 0.2 == 0.3 returns False.

Correct Way to Compare Floating-Point Numbers:

Since floating-point arithmetic can lead to precision issues, it's better to use math.isclose():

import math
print(math.isclose(0.1 + 0.2, 0.3)) # Returns True

This method checks if the numbers are approximately equal within a small tolerance, accounting for floating-point errors.