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Day24 Doubt

Forums > 100 Days of SwiftUI

Hello,

I lost my self in the first test

Go back to project 1 and use a conditional modifier to change the total amount text view to red if the user selects a 0% tip.

I find the solution like this with this solution

.foregroundColor(tipPercentage == 0 ? Color.red : Color.black)

But what i would like to do is to assign to the struct a:

@State private var useRedText = false

and togle the value when the picker is on 0, but i can't find the way to checke the value of the picker slection and toggle my var to fals state when 0 is selected.

Some one could help to find the solution?

Thanks

2      

Instead of using an @State variable for useRedText, try using a computed property. Inside the computed property, you would check the value of the var used to track the Picker's value and return true or false accordingly. Give it a try!

But why use a computed property instead of tagging useRedText with @State?

State properties are for things that should trigger a re-evaluation and possibly a rendering of the View when they change. You aren't changing the value of useRedText and then expecting a rendering of your View; you are already rendering the View and, while doing so, using the value of useRedText to determine what color should be used to draw the text. Make sense?

3      

@Bnerd  

.foregroundColor(tipPercentage == 0 ? Color.red : Color.black)

This works perfectly. Why you should keep it? Code efficiency, you are solving a need with one line of code. Making a computed variables is an idea but you see the extra line of code, correct?

3      

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