How to prepend url with http:// using stringWithFormat in Swift

Question

I\'m building a custom browser using UIWebView.

Use case: User enters \"www.abc.com\" into the address bar. Error below thrown:

Error Domain=WebKitErrorDom         


        

Answer 1

The equivalent of NSString's formatWithString: is just "format:", as shown below, but there is no real need to do that for the example you have given. Just append strings, or use interpolation...

let urlString = "www.abc.com"
var modifiedURLString = NSString(format:"http://%@", urlString) as String
// or just
modifiedURLString = String(format:"http://%@", urlString)
// or
let simpler = "http://" + urlString
// or use string interplotaion
let simplest = "http://\(urlString)"

Answer 2

Just for the sake of being complete here (though of a 4th way), here are your options:

1: Swift way of using NSString's stringWithFormat:

let url = NSString(format: "http://%@", aSuffix)

2: Take advantage of Swift's ability concatenate strings with the "+" operator.

let url = "http://" + aSuffix

3: Use NSString's stringByAppendingString() method.

let url = "http://"
url.stringByAppendingString(aSuffix)

4: String interpolation.

let url = "http://\(aSuffix)"

Answer 3

You can use string interpolation:

let site = "www.abc.com"
let url = "http://\(site)"