I am new to Swift and try to get a feeling for it by trying new things. Now I got stuck with lists. I have two arrays, one is the product and the other the price for each product. I want to fill a list by using a ForEach loop. I use a HStack to have two columns.
To make it a bit more clear, here are the two arrays:
@state private var products = ["Coke", "Fanta", "Sprite", "Water]
private var prices = ["1,43$", "1,22$", "1,64$", "0,45$"]
Now this is a part of my ContentView.swift:
var body: some View {
List{
ForEach(products, id: \.self) { product in
HStack{
Text(product)
Spacer()
Text(price[products.firstIndex(of: product)])
}
}
}
So my plan here is, to fill each cell with the product name by looping through the product array. Then I want to display the corresponding price. For that I take my second Text and fill it with the price. To find the correct Index of the price array, I get the Index from my products array, since they are similar.
That was my solution, but now I am getting an Error for the products.firstIndex(of: product)
.
I am getting following Error:
Value of optional type 'Array.Index?' (aka 'Optional') must be unwrapped to a value of type 'Array.Index' (aka 'Int')
I am not really understanding what this Error is trying to tell me.
Can anybody help?
The correct code looks like this:
struct ContentView: View {
private var products = ["Coke", "Fanta", "Sprite", "Water"]
private var prices = ["1,43$", "1,22$", "1,64$", "0,45$"]
var body: some View {
List{
ForEach(products, id: \.self) { product in
HStack{
Text(product)
Spacer()
Text(self.prices[self.products.firstIndex(of: product)!])
}
}
}
}
}
The reason for your error is that the array could be empty at some point which leads to a crash if you try to read firstIndex in that moment.
Now you have two options:
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