Greeting everyone. I just started my Swiftui journey.

I am trying to get a piece of string from a string variable to display as Text() in Swiftui. In my previous languages I would do something like var subVal = val[1] but it seem this method does not work here.

Is there a way to work around this problem?

//I want the "r" value which is the second element of val 
var val = "orange"
@State var newVal = val[1]

.....
Text("\(newVal)"

CodePudding user response：

you should read the basics at: https://docs.swift.org/swift-book/LanguageGuide/TheBasics.html especially the section on Strings and Characters in Swift at: https://docs.swift.org/swift-book/LanguageGuide/StringsAndCharacters.html and also do the tutorial at: https://developer.apple.com/tutorials/swiftui/

Without knowing the basics you will not go very far in coding your app.

struct ContentView: View {
    var val = "orange"
    @State var newVal = ""
    
    var body: some View {
        Text(newVal)
            .onAppear {
                let index = val.index(val.startIndex, offsetBy: 1)
                newVal = String(val[index])
            }
    }
}

CodePudding user response：

There are many possible ways that you can extract a substring from a string either to get a Character or a new String by using .prefix, .suffix, .index, etc.

var val = "orange"

//using prefix, you will receive a string back
var newVal = val.prefix(2) //"or"

//using suffix, you will receive a string back
var newVal = val.suffix(2) //"ge"

for your case, you can either use the given solution by @workingdog support Ukraine or create a custom extension for reuse

struct ContentView: View {
@State var val = "orange"
var body: some View {
    //you can do String[index] directly
    //the return value is Character, so you need to cast to String
    Text(String(val[1])) //"r"
}
}

//reusable extension
extension StringProtocol {
subscript(offset: Int) -> Character {
    self[index(startIndex, offsetBy: offset)]
}
}