init(exactly:)
Creates a new instance initialized to the given value, if it can be represented without rounding.
Declaration
init?(exactly other: Double)Parameters
- other:
The value to use for the new instance.
Discussion
If other can’t be represented as an instance of Double without rounding, the result of this initializer is nil. In particular, passing NaN as other always results in nil.
let x: Double = 21.25
let y = Double(exactly: x)
// y == Optional.some(21.25)
let z = Double(exactly: Double.nan)
// z == nil