swift-5-Process Control

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

import UIKit

// For-In loop
// 1 traverse the range of numbers
for index in 1 ... 5 {
    println ("\ (index) times 5 is \ (index)")
}

// 2 traverse the array
let names = ["Anna", "Alex", "Brain", "Jack"]
for name in names {
    println ("hello, \ (name)")
}

// 3 traverse the dictionary
let numberOfLegs = ["spider": 8, "ant": 6, "cat": 4]
for (name, legCount) in numberOfLegs {
    println ("\ (name) has \ (legCount) legs")
}

// 4 traversing characters
for character in "hello" {
    println (character)
}

// For loop
for var index = 0; index <3; index ++ {
    println ("index is \ (index)")
}

// While do-while
var i = 0
do {
    i ++
} while (i <3)

while (i <5) {
    i ++
}

// Conditional statements
var temperatureInFahrenheit = 30
if temperatureInFahrenheit <= 32 {
    println ("It ‘s very cold")
}

switch temperatureInFahrenheit {
    case 1 ... 20:
        println ("1 ... 20")
    case 23, 30:
        println ("come here")
        fallthrough // By default, it will not enter the next judgment. Adding this keyword allows the match to directly enter the next judgment
    default:
        println ("default")
        break // jump out of switch
}

var somePoint = (1, 1)
switch somePoint {
    case let (x, y) where x == y:
        println ("equal")
    default:
        break
} 

swift-5-Process Control