Function returns another function

function-returns-function.swift

import UIKit

// Function returns another function.

/* 
    Reference: https://www.youtube.com/channel/UC-d1NWv5IWtIkfH47ux4dWA, The Swift Guy
*/

func shouldVerify(_ chooseAction: Bool) -> (String, String) -> String {
    
    func verifyThenSendMessage(_ verifyNumber: String, _ sendMessage: String) -> String {
        // Verify number first then send message logic...
        return "Verification conducted for number: \(verifyNumber), Message sent: \(sendMessage)"
    }
    
    func sendMessageOnly(_ userNumber: String, _ sendMessage: String) -> String {
        // No need to veify number just Send it to that particular number
        return "Verified number: \(userNumber), Message sent: \(sendMessage)"
    }
    
    return chooseAction ? verifyThenSendMessage : sendMessageOnly
}

let sendVerificationMessage = shouldVerify(true)
sendVerificationMessage("9876543210","Please enter the provided OTP");

let sendLoginMessage = shouldVerify(false)
sendLoginMessage("9876543210","Welcome back!");