I am new to Swift, and tried to solve this problem far too long. I have the following declared:

@State private var loanAmount = "0"    
private var arr = [String](repeating: "", count: 10)

I also tried the array with a property wrapper like this
@State private var arr = [String](repeating: "", count: 10) and 
that also didn't work'

The body of my View where I am getting the errors shown in the
code between ***.  Can anyone help?

    var body: some View {
    NavigationView {
        Form {
            HStack { //*** Type '()' cannot conform to 'View'; only struct/enum/class types can conform to protocols *** 
                Text("Company Name:")
                TextField("", text: self.$companyName)
            }
            HStack {
                Text("Loan Amount:")
                TextField("", text: self.$loanAmount)
                arr[0] = loanAmount //*** Cannot assign through subscript: 'self' is immutable ***
                }
            }

Is your array arr also declared with @State? If not, then as the error says, you cannot change its value as the Struct is immutable.