今天練習(xí)代碼：
import UIKit
class ViewController: UIViewController {
@IBOutlet weak var op1: UITextField!
@IBOutlet weak var op2: UITextField!
@IBOutlet weak var result: UILabel!
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.
}
@IBAction func add(sender: AnyObject) {
let _op1 = Int(op1.text!)
let _op2 = Int(op2.text!)
let resultValue = _op1! + _op2!
result.text = String(resultValue)
}
}
學(xué)到的東西：
toInt() 已經(jīng)過(guò)時(shí)，現(xiàn)在的話，需要使用Int(String) 轉(zhuǎn)換
var 與 let 的區(qū)別
為什么用var 會(huì)有警告，不是很清楚，求大神指點(diǎn)
