Pass data from ViewController to TableViewController using segue - ios

Question

I have created a Calculator using Swift in Xcode. I would like to add another functionality to it, I already have a history label that displays the previous calculations. I would like to pass the data that displays in that history label into a TableViewController and for each calculation my history label shows to have it add each data into my TableViewController. I know I should be able to use perform segue, but I'm not exactly sure. Here is my code so far:
ViewController.swift
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var displayLabel: UILabel!
#IBOutlet weak var HistoryLabel: UILabel!
var userIsTypingNumbers = false
#IBAction private func NumbersEntered(_ sender: UIButton) {
//know what number is being pressed
let digit = sender.currentTitle!
//if user is typing a number, do this.
if userIsTypingNumbers{
//specify what number is being pressed
let textCurrentDisplay = displayLabel.text!
//append the another number onto the previous number.
displayLabel.text = textCurrentDisplay + digit
} else {
displayLabel.text = digit
}
userIsTypingNumbers = true
}
var displayValue: Double {
get {
return Double(displayLabel.text!)!
}
set {
displayLabel.text = String(newValue)
}
}
private var calculations = PerformCalculations()
#IBAction func Enter(_ sender: UIButton) {
//perform the calculations
if userIsTypingNumbers{
calculations.setOperand(operand: displayValue)
userIsTypingNumbers = false
}
if let mathematicalSymbol = sender.currentTitle {
calculations.performOperation(symbol: mathematicalSymbol)
}
HistoryLabel.text = HistoryLabel.text! + String(sender.currentTitle!);displayValue = calculations.result
HistoryLabel.text = HistoryLabel.text! + String(displayValue)
}
#IBAction func Clear(_ sender: UIButton) {
//clear display to 0.
displayLabel.text = "0"
HistoryLabel.text = ""
}
#IBAction func Delete(_ sender: UIButton) {
//deleting last typed number, if user messed up.
let name: String = self.displayLabel.text!
//count number of characters.
let stringLength = name.characters.count
let substringIndex = stringLength - 1
displayLabel.text = (name as NSString).substring(to: substringIndex)
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if (segue.identifier == "History"){
if let destinationVC = segue.destination as? HistoryClassViewController{
destinationVC
}
}
}
}
I have started attempting a prepare for segue function, but not sure how to make it work. Any help would be much appreciated. Hopefully this makes sense. Here is a picture of how my Calculator is laid out in Xcode:

Answer 1

Create in your HistoryClassViewController field like
var someData: Any!
Then:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "History" {
if let destinationVC = segue.destination as! HistoryClassViewController {
destinationVC.someData = something
}
}
}
Then to perform segue in place you wants to type this:
self.performSegue(withIdentifier: "History", sender: self)
Hope it helps

Answer 2

Here is thing Take one String Variable as global Variable in HistoryClassViewController class
example:
class HistoryClassViewController: UITableViewController{
var dataString:String!
//............Continue code
//............
Now Write this Method in ViewController class
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if (segue.identifier == "History"){
if let destinationVC = segue.destination as? HistoryClassViewController{
destinationVC.dataString = displayLabel.text!
}
}
}
Finally access dataString value in TableViewController.