Вот решение:
func nearlyEqual(a: Float, b: Float, epsilon: Float) -> Bool {
let absA = abs(a)
let absB = abs(b)
let diff = abs(a - b)
if a == b {
return true
} else if (a == 0 || b == 0 || absA + absB < Float.leastNonzeroMagnitude) {
// a or b is zero or both are extremely close to it
// relative error is less meaningful here
return diff < (epsilon * Float.leastNonzeroMagnitude)
} else {
return diff / (absA + absB) < epsilon
}
}
Тогда вы можете использовать его следующим образом:
print(nearlyEqual(a: 1.2, b: 1.4, epsilon: 0.2))
Это вернет true.