Iterate through files in a folder and its subfolders using Swift's FileManager

Use the nextObject() method of enumerator:

while let element = enumerator?.nextObject() as? String {
    if element.hasSuffix("ext") { // checks the extension
    }
}

Nowadays (early 2017) it's highly recommended to use the – more versatile – URL related API

let fileManager = FileManager.default

do {
    let resourceKeys : [URLResourceKey] = [.creationDateKey, .isDirectoryKey]
    let documentsURL = try fileManager.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)
    let enumerator = FileManager.default.enumerator(at: documentsURL,
                            includingPropertiesForKeys: resourceKeys,
                                               options: [.skipsHiddenFiles], errorHandler: { (url, error) -> Bool in
                                                        print("directoryEnumerator error at \(url): ", error)
                                                        return true
    })!

    for case let fileURL as URL in enumerator {
        let resourceValues = try fileURL.resourceValues(forKeys: Set(resourceKeys))
        print(fileURL.path, resourceValues.creationDate!, resourceValues.isDirectory!)
    }
} catch {
    print(error)
}

I couldn't get pNre's solution to work at all; the while loop just never received anything. However, I did come across this solution which works for me (in Xcode 6 beta 6, so perhaps things have changed since pNre posted the above answer?):

for url in enumerator!.allObjects {
    print("\((url as! NSURL).path!)")
}