Swift learning

import Foundation
import Glibc

/*
var test1: Int = 1 
var test2: Double = 1.192837465
var test3: Float = 1.192837465
var test4: Bool = true
var test5: String = "test"

print(type(of: test4));

    /*
    print(π)
    print(你好)
    print(🐶🐮 )
    print(dogcow)
    
    print(Int8.min); print(Int8.max)
    print(Int.min); print(Int.max)
    print(Int16.min); print(Int16.max)
    print(Int32.min); print(Int32.max)
    print(Int64.min); print(Int64.max)
    
    print(UInt8.min); print(UInt8.max)
    print(UInt.min); print(UInt.max)
    print(UInt16.min); print(UInt16.max)
    print(UInt32.min); print(UInt32.max)
    print(UInt64.min); print(UInt64.max)
    */

*/
/*
let maximumNumberOfLoginAttempts: Int = 10
var currentLoginAttempt: Int = 0

var welcomeMessage: String
welcomeMessage = "Hello"

let π = 3.14159
let 你好 = "你好世界"
let 🐶🐮 = "dogcow"
var dogcow = "🐶🐮 "

print(π)
print(你好)
print(🐶🐮 )
print(dogcow)

print(Int8.min); print(Int8.max)
print(Int.min); print(Int.max)
print(Int16.min); print(Int16.max)
print(Int32.min); print(Int32.max)
print(Int64.min); print(Int64.max)

print(UInt8.min); print(UInt8.max)
print(UInt.min); print(UInt.max)
print(UInt16.min); print(UInt16.max)
print(UInt32.min); print(UInt32.max)
print(UInt64.min); print(UInt64.max)


var convertedNumber: Int? = 5
if convertedNumber != nil {
    print("convertedNumber has an integer value of \(convertedNumber!).")
}
*/

//Error handling
enum CalculationError: Error {
    case aIsMissing
    case bIsMissing
    case divideByZero
}

func calculateTwoNumbers(a: Double, b: Double) throws -> Double {
    let result: Double?;
    
    if b == 0 {
        throw CalculationError.divideByZero;
    }
    
    result = a/b;
    
    return result!;
}

do {
    let calculationResult: Double?
    
    try calculationResult = calculateTwoNumbers(a: 1, b: 4);
    print("\(calculationResult!)");
} catch {
    print("can't divide by 0!");
}


//let age = -3
//assert(age >= 0, "A person's age can't be less than zero.")