Parse a ip in swift - ios

Question

I'm trying to parse an for a validation purpose,
like
var ip = "192.168.1.2"
So I need to pass this ip in a api call for the response , for that I need to pass ip's from "192.168.1.[1-255]" till 255, to get a response.
My question how I achieve this, need I to spilt the string by '.' and move into an array and to search with index for 4. till 255.
Or is there another method to achieve it?

Answer 1

//If you have a fixed local ip like "192.168.1.x"
for i in 1...255 {
let ip = "192.168.1.\(i)"
// Call the API with ip
}
//if you get local ip from other service or from refference, then
let ip = "192.168.1.10"
let ipAry = ip.components(separatedBy: ".")
let ipStr = "\(ipAry[0]).\(ipAry[1]).\(ipAry[2])"
for i in 1...255 {
let newIP = "\(ipStr).\(i)"
// Call the API with ip
}

Answer 2

General idea:
Extract everything from start to last '.'
Run a for loop and generate numbers from 1 to 255.
Cast the number generated in step2 to a string and append it to the result of step1.
Hit the api with the final string and check for a response.
If you get a response then break the loop and work with the response object outside the loop.
You can perform step1 with string methods or regex. Although string methods will be better, i'll give the regex example.
Step1 with regex:
^(.*?\.)\d+$
Desired string will be captured as group 1.
Demo:
https://regex101.com/r/gQKs0w/1

Answer 3

No need splitting and iterations
func isValidIp(ip : String) -> Bool {
let allowedIpPrefix = "192.168.1."
if ip.hasPrefix(allowedIpPrefix) {
let suffix = String(ip.characters.dropFirst(allowedIpPrefix.characters.count))
if let suffixValue = Int(suffix){
//check for "0" prefix because 192.168.1.01 is invalid ip but Int("01") will return valid 1
if (1 ... 255).contains(suffixValue) && !suffix.hasPrefix("0") {
return true
}
}
}
return false
}