Swift Basics

Swift is an Open Source, powerful language for mac OS, iOS.

Swift 3 is the major release developed at Swift.org.

Declaring Constants :

let maximumMembers = 5

var minimumMembers = 2

let pi = 3.1416

Type Annotations :

var username: String

username = "Srinivas Nidadavolu"

println(username) // prints Srinivas Nidadavolu

Constant value cannot be changed.

var username = "SRINIVAS NIDADAVOLU"

username = "KARUNA" // compile time error - username cannot be changed

Comments :

Comments in swift is similar to other programming languages like java, javascipt and c etc.

// for comment

/* this is also a comment*/

Semicolons:

Swift doesnt need a semicolon (;) after every statement. Its optional. If your using multiple statements in the same line, then its required.

Data Types :

32 Bit and 64 bit platforms :

32 bit platform:

Int is Int32

UInt is UInt32

64 bit platform:

Int is Int64

UInt is UInt64

Booleans:

let userActive = true

if userActive{

println("user is active")

}else{

println("user is inactive")

}

Optionals:

Swift handles the absence value with Optionals.

var userStr = String? = nil

import Cocoa

var userStr : String?=nil

if  userStr!=nil {

println(userStr)

}else{

println("It contains nil")

}