user1923938 - 1 year ago 100
Swift Question

# Making Types in Swift Floating Point Value and "X": Polloquin Exercise Notation

I am trying to code times for weightlifting. There are four phases to a repetition:

Eccentric (Time spent lowering the weight)
Bottom (Time spent at the bottom of the lift)
Concentric (Time spent lifting the weight)
Top (Time spent a the top of the lift)

It will be formatted like this: 1030

so in that example, a person would take 1 second lowering the weight, then immediately lift the weight taking three seconds, reach the end of the movement and stop to complete one repetition.

``````class rep {

var eccentric:Float //  time spent lowering the weight
var bottom:Float // time spent at the bottom of the repetition.
var concentric:Float  // time spent raising the weight.
var top:Float // time spent at the top of the repetition.

var notation:String

init(timeDown:Float, timeBottom:Float, timeUp:Float, timeTop:Float)        {

eccentric = timeDown
bottom = timeBottom
concentric = timeUp
top = timeTop

notation = "\(eccentric),\(bottom),\(concentric),\(top)"

}

func displayNotation() -> String{

print(notation)

return notation

}

}

class ViewController: UIViewController {

let repetition = rep(timeDown: 1,timeBottom: 0,timeUp: 3,timeTop: 0)

repetition.displayNotation()

}
``````

this outputs 1.0,0.0,3.0,0.0

What I want to do is have an additional character "X" to indicate "as fast as possible." I am thinking that I would need to create a new type for this? So I want to be able to accept a float or that particular character... totally baffled as to how to go about this.

Thanks for any response

Ok, so this is one way to go about it.

First create a model for your data:

``````class Data {
var string: String
var value: Double?

init(string: String, value: Double?) {
self.string = string
self.value = value
}
}
``````

The `string` will be used for displaying, and the `value` will be used for calculations. I set the `value` as an optional which will be explained in a moment.

Then create a data source for the `UIPickerView` and populate it:

``````var dataSource: [Data] = []

// Adds all values from 0.0 to 9.9 and the "additional character".
func populateDataSource() {
for i in 0..<100 {
let value = Double(i) / 10
dataSource.append(Data(string: value.description, value: value))
}
dataSource.append(Data(string: "X", value: nil))
}
``````

What I've done here is set the `value` for the additional character to `nil`.

Assuming you've already configured your `UIPickerView`, add the `UIPickerViewDataSource` methods:

``````func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}

func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return dataSource.count
}

func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return dataSource[row].string
}

// This variable will be used to hold the user selection.
var selected: Data?

// If you want it to default to e.g. 0.0, just create it as:
// var selected = dataSource.first

func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
self.selected = dataSource[row]
}
``````

And now you can do your calculations based on the selection:

``````// You should check that selection isn't nil before doing this.
// Depends on how you create it.

if let value = selection.value {
// The selection has a value between 0.0 and 9.9.
// So, do your standard calculations for that.
} else {
// The selection does not have a value, which means it's your custom character.
// So, take that into account in your calculations.
}
``````
Recommended from our users: Dynamic Network Monitoring from WhatsUp Gold from IPSwitch. Free Download