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

Question

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 a

Answer 1

When a float is negative (including -0.0 and -inf), it uses the same sign bit as a negative int. This means you can compare the integer representation to 0, eliminating the need to know or compute the integer representation of -0.0:

if(f == 0.0) {
  if(Float.floatToIntBits(f) < 0) {
    //negative zero
  } else {
    //positive zero
  }
}

That has an extra branch over the accepted answer, but I think it's more readable without a hex constant.

If your goal is just to treat -0 as a negative number, you could leave out the outer if statement:

if(Float.floatToIntBits(f) < 0) {
  //any negative float, including -0.0 and -inf
} else {
  //any non-negative float, including +0.0, +inf, and NaN
}