Save file in document directory in swift 3?

Please think the other way round.

URL is the recommended way to handle file paths because it contains all convenience methods for appending and deleting path components and extensions – rather than String which Apple has removed those methods from.

You are discouraged from concatenating paths like path = path + name. It’s error-prone because you are responsible for all slash path separators.

Further you don’t need to create a file with FileManager. Data has a method to write data to disk.

let fileManager = FileManager.default
do {
    let documentDirectory = try fileManager.url(for: .documentDirectory, in: .userDomainMask, appropriateFor:nil, create:false)
    let fileURL = documentDirectory.appendingPathComponent(name)
    let image = #imageLiteral(resourceName: "Notifications")
    if let imageData = image.jpegData(compressionQuality: 0.5) {
        try imageData.write(to: fileURL)
        return true
    }
} catch {
    print(error)
}
return false

Alternatively make the function throw and hand over the error to the caller

func saveFile(with name: String) throws {
    let fileManager = FileManager.default
    let documentDirectory = try fileManager.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)
    let fileURL = documentDirectory.appendingPathComponent(name)
    let image = #imageLiteral(resourceName: "Notifications")
    guard let imageData = image.jpegData(compressionQuality: 0.5) else { throw URLError(.cannotDecodeContentData) }
    try imageData.write(to: fileURL)
}