assign - combine

ViewController.swift

// Create a new search subject with a default value
class ViewController: UIViewController {
  
  @Published var buttonTapSubject: Int = 0
  @Published var textSubject: String = ""
  var cancellables = Set<AnyCancellable>()
  let button = UIButton()
  let label = UILabel()
  
  override func viewDidLoad() {
    super.viewDidLoad()
    /* layout code removed for brevity */
    
    $buttonTapSubject
      .map{ String($0) }
      .assign(to: &$textSubject) // assign to another publisher

    $textSubject 
      .compactMap { $0 }
      .assign(to: \.text, on: label) // assign to property on label
      .store(in: &cancellables)
  }
  
  @objc func didTap() {
    buttonTapSubject += 1
  }
  
}