Turn a TextField's text into a double in Swift UI

App Development
1

I working on an app that takes user input and uses that input for calculation.

I want to take the text string and turn out into a double. Everything I have found online points to this code:

TextField(“Length”, text: $project.length)

let length = Double(lengthTextField.text ?? " ") 0.0

When I put this code into a button function I get myriad errors. I thought the problem was that ‘text’ part of TextField said ‘$.project.length’. So I tried writing the following:

let length = Double($project.length.text ?? " ") 0.0

let length = Double($project.length ?? " ") 0.0

let length = Double(project.length.text ?? " ") 0.0

let length = Double(project.length ?? " ") 0.0

These all produce errors. Can someone please tell me the correct way to write this?

2

Like this:

let length = Double(project.length) ?? 0.0

You have to try to convert something (in this case project.length) to Double first, then check if it succeeded with nil coalescing and then, if it didn’t, default to 0.0.

3

Thanks, Rooster, that works.