Check if an URL has got http:// prefix

You can use the - (BOOL)hasPrefix:(NSString *)aString method on NSString to see if an NSString containing your URL starts with the http:// prefix, and if not add the prefix.

NSString *myURLString = @"www.google.com";NSURL *myURL;if ([myURLString.lowercaseString hasPrefix:@"http://"]) {    myURL = [NSURL URLWithString:myURLString];} else {    myURL = [NSURL URLWithString:[NSString stringWithFormat:@"http://%@",myURLString]];}

I'm currently away from my mac and can't compile/test this code, but I believe the above should work.

NSString * urlString = ...;NSURL * url = [NSURL URLWithString:urlString];if (![[url scheme] length]){  url = [NSURL URLWithString:[@"http://" stringByAppendingString:urlString]];}

Better to use the scheme property on the URL object:

extension URL {    var isHTTPScheme: Bool {        return scheme?.lowercased().contains("http") == true // or hasPrefix    }}

Example usage:

let myURL = URL(string: "https://stackoverflow.com/a/48835119/1032372")!if myURL.isHTTPScheme {    // handle, e.g. open in-app browser:                present(SFSafariViewController(url: url), animated: true)} else if UIApplication.shared.canOpenURL(myURL) {    UIApplication.shared.openURL(myURL)}