Plz tell me why this output?

Question

https://code.sololearn.com/cCMJO1KbXZk2/?ref=app

What is the output?

Answer 1

Literals ("4.2") are of type double, not float. And when you convert 4.2 to a float, to store it in a, you lose some precision, and here it happened to change the absolute value.

https://code.sololearn.com/cvr52qOXURyx/?ref=app