Replace an image file with a new image - ios

Question

Is there a way to replace an existing image file's image, that exists in the directory?
In a method I have I retrieve what I call "default" images from the app's directory. Now, the app lets the user take images with a custom camera and I want to be able to use the same retrieve method (with the default file names) but with the new images taken with the camera.
Any ideas?
Thanks!
UPDATE:
#IBAction func show(_ sender: Any) {
image.image = UIImage(named: "image.jpg")
}
#IBAction func saveImages(_ sender: Any) {
self.saveImageDocumentDirectory()
}
func saveImageDocumentDirectory() {
let fileManager = FileManager.default
let paths = (NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as NSString).appendingPathComponent("image.jpg")
let image = UIImage(named: "image.jpg")
print(paths)
let imageData = UIImageJPEGRepresentation(image!, 0.5)
fileManager.createFile(atPath: paths as String, contents: imageData, attributes: nil)
}
However, I don't know how to retrieve it (if that even is the correct way to save an image to an existing file).

Answer 1

func saveImageDocumentDirectory() {
let fileManager = FileManager.default
let paths = (NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as NSString).appendingPathComponent("image.png")
let image = UIImage(named: "image.png")
let imageData = UIImageJPEGRepresentation(image!, 0.5)
fileManager.createFile(atPath: paths as String, contents: imageData, attributes: nil)
}

Answer 2

You can use this code on swift 4 and it works when overwriting a file :)
let fileManager = FileManager.default
let path = URL(string: "your file path here")
do {
let image = UIImage(named: "sampleImage")
if let imageData = image?.jpegData(compressionQuality: 0.5) {
try imageData.write(to: path, options: Data.WritingOptions.atomic)
}
} catch {
//handle error here
}