What Is Swift Programming?
Swift is a powerful, open-source, safe,
multi-paradigm and compiled programming language designed and developed by Chris Lattner, Apple Inc.
It is a safe, fast and interactive programming
language for iOS, macOS, watchOS, tvOS and Linux.
Swift Programming offers better type safety, security and performance.
Some
Programming Patterns -
ü Swift
variables are always initialized before use.
ü Swift
array indices are checked for out-of-bounds errors.
ü Swift
is an alternative to the Objective-C language.
ü Memory
is managed automatically.
ü Error
handling allows controlled recovery from unexpected failures.
Swift
Version History -
Mid 2010 - Development begins
Jun 2014 - Apple announces Swift at WWDC 2014
Sep 2014 - Apple releases Swift 1.0
Oct 2014 - Swift 1.1 is released
Apr2015 - Swift 1.2 is released
Mar 2017 - Apple releases Swift 3.1
June 2017 - Apple announces Swift 4.0 at WWDC 17
Is Swift Object Oriented Programming?
Yes! Swift is an Object-Oriented Programming
language.
What's New Features in Swift 4.0?
ü Faster,
easier to use Strings that retain Unicode correctness
ü Smart
key paths for type-safe, efficient, extensible key value coding for Swift types
ü Added
some enhancements to creating dictionary and Set types
ü Extends
to supports of serialization to Struct
ü Tuples
and multiple return values
ü Structs
that support methods, extensions, and protocols
ü Native
error handling using try/catch/throw
What Are the Advantages of Swift?
ü Swift
is safe
ü Swift
is fast
ü Swift
is open source
ü Swift
is approachable
ü Swift
is easy to learn
What Is The Difference Between Swift And Objective-C Language?
Swift
Programming-
In a swift programming, the variables and
constants are declared before use.
In a swift programming, “var” keyword used for
variable and “let” keyword for constant.
In a swift programming, no need to end code with
semi-colon
In a swift programming, does not require creating
a separate interface like Objective-C.
In a swift programming, we can define methods in
class, structure or enumeration.
Objective-C
Programming-
In objective-C programming, we need to end code
with semi-colon
In objective-C programming, we can declare
constant as int and variable as NSString.
How You define variables in Swift?
The “var” keyword is used for declaring variables
and variables must be declared before they are used.
var
helloMsg = "This
is Anil, How Are You?"
What Is the significance of “?” in swift?
The question mark (?) is used during the declaration of a property. If the property
does not hold a value, the question mark (?)
helps to avoiding application errors.
Example looks like -
class
Employee {
var certificate
: [Certificates]?
}
let
employee = Employee();
Example 2 -
let
middleName : String?
= nil
let
lastName : String
= "Singh"
let
name : String
= middleName ?? lastName
What Is Type Aliasing in Swift?
This borrows very much from C/C++. It allows us
to alias a type, which can be useful in many particular contexts.
typealias
sample = UInt16
What Is a deinitializer in Swift?
If you want to perform an additional clean-up of your classes, it is
possible to define a block called deinit.
Syntax
-
deinit
{
//Your cleanup statement here.
}
How Multiple Line Comment Can Be Written In Swift?
The Nested multiline comments enable you to
comment out large blocks of code quickly and easily.
Use an opening (/*: ) and closing ( */) comment
and it looks like -
/*:
The above forward slash (/) and an asterisk (*) then a colon (:) is
opening comment - (/*:)
…
The below an asterisk (*) and forward slash is closing comment – (*))
*/
What Is difference between “let” and “var” declaration?
The “var”
keyword is used for declaring variables while “let” keyword is used to declare constants.
Both variables and constants must be declared
before they are used.
Once assigned value in the constant, cannot be change but
once assigned value in the variables, it can be change.
Var
helloMsg = “This
is Anil,
How Are
Yo?” //
declared variable
let
port = 8080;
//declared
constant
How To convert NSMutableArray to Swift Array in swift?
The following code looks like -
var
mutableArray = NSMutableArray(array:
["Anil", "Sunil",
"Sushil"])
var
swiftArray = mutableArray
as NSArray
as! [String]
How To convert NSArray to NSMutableArray in swift?
The following code looks like -
let
array_1: NSArray
= [“Anil”, “Sunil”,
“Sushil”]
var
mutableArray = NSMutableArray(array:array_1)
print(mutableArray)