Control Flow in Swift

control_flow_ in_swift

// Playground - noun: a place where people can play

import UIKit

// Flow management in Swift
// Parentheses are optional, curly braces are mandatory.
// condition must evaluate as a boolean.

var a = 5
var b = 10

if a < b {
    println("a is less than b.")
} else if a > b {
    println("a is bigger than b.")
} else {
    println("a is equal to b")
}


// Switch statements are recommended.

switch a {
case 1...10:
    println("\(a) is between 1 and 10")
default:
    println("\(a) is not between 1 and 10")
}

var c: Character = "w"
switch c {
case ".", "!", "@", "#", "$":
    println("\(c) is a special character.")
case "a", "e", "i", "o", "u":
    println("\(c) is a vowel.")
case "b", "c", "d", "f", "g", "h", "j", "k", "l", "m",
"n", "p", "q", "r", "s", "t", "v", "w", "x", "y", "z":
    println("\(c) is a consonan.t")
default:
    println("\(c) is neither a vowel, nor a consonant")
}


// Loops

// Closed inclusive range. Includes both sides.
for i in 1...100 {
    println(i)
} // will print 1,2,3,,,,,100

// Half open range operator. Inludes the left side, not the right side.
for i in 1..<100 {
    println(i)
} // will print 1,2,3,,,,,99


// Looping over characters of a string
for c in "Hellow World!" {
    println(c)
}

var i = 0

while i < 10 {
    println(i)
    i = i+1
}

// do while executes at last once.
do {
    println(i)
    i = i+1
} while i < 10


// Functions

func f1 () {
    println("Hello World!")
}

f1()

func f2 (name : String){
    println("Hello \(name)!")
}

f2("Ramtin")


func f3 (name : String, age : Int) {
    println("Hello \(name)! Im \(age) yera(s) old.")
}

f3("Ramtin", 100)


func f4 (firstName : String, lastName : String) -> String {
    return ("\(firstName) \(lastName)")
}

println(f4("Jogn", "Doe"))


// If a defalut avalue is specified in the parameters
// , the parameter should be named while calling the function

func f5 (name : String = "John Doe") -> String {
    return ("Hello \(name)")
}

println(f5(name: "Ramtin"))

func f6 (a : Int = 4, b : Int = 5){
    println("result is: \(a*b)")
}

f6() // 20
f6(a: 10) // 50
f6(b: 10) //40
f6(a:10, b:20) // 200