swift - Delay using DispatchTime.now() + float?

Question

What exactly is going on with DispatchTime.now()

How come I can't assign the time to wait as a variable?

And How Could I use a variable ?

Given error >>>

Binary operator '+' cannot be applied to operands of type 'DispatchTime' and 'Float'

var time : Float = 2.2 // <---time 

@IBAction func buttonPressed(_ sender: Any) {

    let when = DispatchTime.now() + 2.2 // <---- THIS IS OKAY
    DispatchQueue.main.asyncAfter(deadline: when){

        print("Hello")
    }

    let whenWhen = DispatchTime.now() + time // <---- THIS IS NOT OKAY
    DispatchQueue.main.asyncAfter(deadline: whenWhen){

        print("Hello")
    }
}

Answer 1

DispatchTime.now() is a double. You cannot add a float and a double value together. (A small explanation about why can't you add values with different types can be found here).

Replace

var time: Float = 2.2

with

var time: Double = 2.2

And it will work fine.