import UIKit
class ViewController: UIViewController {
@IBOutlet weak var textField: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
textField.delegate = self
let stringArray = ["1", "2", "3", "4", "5", "6", "7", "8", "9", "10"]
let even = stringArray.map { Int($0)!
}.filter {
$0 % 2 == 0
}
print(even)
}
}
extension UIViewController: UITextFieldDelegate {
//在每次用户按下键盘，字母在屏幕上显示出来之前被调用
public func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
// 1. 每次的输入转换成一个整数
if let n = Int(string) {
// 2. 判断是否能够被2整除
if n % 2 == 0 {
print(n)
}
}
return true
}
}
过滤
在同个时间维度进行处理
资料来源：理解Reactive编程思想
