Parse a string with specific condition - ios

Question

How can I trim my string which is in this form:
https://xxx.kflslfsk.com/kjjfkskfjksf/v1/files/media/93939393hhs8.jpeg
to this?
media/93939393hhs8.jpeg
I want to remove all the characters before the second to last slash /.
I can use stringByTrimmingCharactersInSet but I don't know how to specify the condition that I want:
let trimmedString = myString.stringByTrimmingCharactersInSet(
NSCharacterSet.whitespaceAndNewlineCharacterSet() // what here in my case ??
)
The above is for removing the white spaces, but that is not the case here.

Answer 1

Since the string is an URL get the path components, remove anything but the last 2 items and join the items with the slash separator.
if let url = NSURL(string:"https://xxx.kflslfsk.com/kjjfkskfjksf/v1/files/media/93939393hhs8.jpeg"), pathComponents = url.pathComponents {
let trimmedString = pathComponents.suffix(2).joinWithSeparator("/")
print(trimmedString)
}

Answer 2

You're not trimming, you're parsing.
There's no single call that will do what you want. I suggest writing a block of code that uses componentsSeparatedByString("\n") to break it into lines (one URL per line), then parse each line separately.
You could use componentsSeparatedByString("/") on each line to break it into the fragments between your slashes, and then assemble the last 2 fragments together.
(I'm deliberately not writing out the code for you. You should do that for yourself. I'm just pointing you in the right direction.)
You might also be able to use NSURLComponents to treat each line as a URL, but I'm not sure how you'd get the last part of URL before the filename (e.g. "media " or "lego") with that method.