#35.換算App: 測測BMI，為自己的健康把關吧~~~

➤作業目的：學習字串轉數字，optional binding，收鍵盤

閒來無事就來測一下BMI，是否符合標準值吧！
以下貼心附上我在網路上擷取的BMI範圍供大家參考唷！

上表源自網路

import UIKit
class ViewController: UIViewController {
@IBOutlet weak var heightTextField: UITextField!
@IBOutlet weak var weightTextField: UITextField!
@IBOutlet weak var BMILabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
@IBAction func calculate(_ sender: Any) {

let heightText = heightTextField.text!
let weightText = weightTextField.text!
let height = Double(heightText)
let weight = Double(weightText)

if height != nil, weight != nil{
let heightMeter = height! / 100
let bmi = weight! / ( heightMeter * heightMeter )
BMILabel.text = String(format:"%.2f",bmi)
}

view.endEditing(true)

}

}

vinnieisafish/BMI-app