boolean - Convert String to Bool in Swift - via API or most Swift-like approach

Question

Is there an API to convert most possible String representations of Boolean values (e.g. "True", "true", "False", "false", "yes", "no", "1", "0") into a Bool in Swift?

If not, what would be the most Swift-like approach to coding this from scratch? Would it be a functional map() operation? Or something else?

The original source data in this instance is JSON, but I'm interested in the crux of solving the problem in the most Swift-like way possible and hence learning more about the language in the process.

Answer 1

There is not built in way AFAIK. Similar method to standard toInt() could be:

extension String {
    var bool: Bool? {
        switch self.lowercased() {
        case "true", "t", "yes", "y":
            return true
        case "false", "f", "no", "n", "":
            return false
        default:
            if let int = Int(string) {
                return int != 0
            }
            return nil
        }
    }
}