How do I check if a zero is positive or negative?

By | July 29, 2019


Is it possible to check if a float is a positive zero (0.0) or a negative zero (-0.0)?

I’ve converted the float to a String and checked if the first char is a '-', but are there any other ways?


Yes, divide by it. 1 / +0.0f is +Infinity, but 1 / -0.0f is -Infinity. It’s easy to find out which one it is with a simple comparison, so you get:

if (1 / x > 0)
    // +0 here
    // -0 here

(this assumes that x can only be one of the two zeroes)

Rate this post

Leave a Reply

Your email address will not be published. Required fields are marked *