Swift Basic Programming

Contents

• Import module
• Type (Int, String, Double, Float)
• var, let
• Cast (Int to Double)
• String
• Array
• if, while, repeat, for
• for – where
• for in
• switch, switch range
• label
• do

Sample

This programming is by Playground

import UIKit
import Foundation
import Darwin
// Module import

var str = "Hello, playground"

var num : Int = 12
var num2 = 18
num2 = 19
var num3 : Double = 10.4
var num4 : Float = 4.2

var width = 18.5, height = 171.4, category = "S"

let name : String = "DJ"

let a : Double = Double(3)

let m: UInt = 1000
let n: Int8 = 64
print(m == n)

let spaceKeys = "command=\u{2318}"

let strtest = "\(n) is"
print(strtest)

let message = "Hello," + name
print(message, strtest, spaceKeys)


// Array
var arr1 = [2,3,4,5,6,7,8]
var arr2 : [Int] = [1,2,3,4,5,6]

var s = [String]()
var s1 : [String] = []

let b = ["Nogizaka", "Keyakizaka", "Hinatazaka"]
print(b[1])
// b[1] = "Yoyogi"

var country = ["US", "UK"]
country.append("JP")
country += ["CN", "SG"]
print(country)


var c = 1
// a++
c = c + 1
// camel case
var `Int` = 3
print(`Int`)

var arr3 : [Int]
var aar4 : Array<Int>

/* Comment */
let d : Int = 4
if d > 0 {
    print(d)
} else {
    print("minus")
}
let e = d >= 0 ? d : -d

var countb = 4
while countb <= 0 {
    countb = countb-1
    print(countb)
}

var n1 = 7
repeat {
    print("\(n1)")
    n1 = n1 - 1
} while n1 > 1

// for
for i in 1..<5 {
    print(i)
}

for i in 1...5 {
    print(i)
}

for i in 1..<32 where i % 3 != 0 {
    print(i, terminator: " ")
}

let name2 = "Kazuma"
let group = ["Aqua", "Kazuma", "Dakunes", "Megumin", "Yunyun"]
for s in group {
    if name2 == s {
        print("\(s) is here")
        break
    }
}

// switch
let el = 5
switch n {
case 0: print("none")  // no need to use break
case 1: print("1")
case 2, 3: print("A few")
case 4, 5:
    print("some")
case 6: break
default:
    print("default others")
}

// switch 2
let ave = 55
let score = 60

switch score {
case 0..<ave: print("Less average")
case ave..<70: print("Good")
case 70..<90: print("Great")
case 90...100: print("Excellent")
default: print("Error")
}


// label loop
var index = 1
loop: while true {
    if (index > 10) {
        break loop
    }
    print(index)
    index += 1
}

// if label
let age2 = 50
jump: if age2 < 60 {
    if age2 < 55 {
        print("Zaikei OK")
        break jump
    }
    print("Over 55")
}

// do block
var x = 100
var xb = 0
var xc = 200
if x >= 0 {
    xb += x
    do {
        let t = x; x = c; c = t
    }
}