Swift notes and useful resources

 swift(ios dev..)

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• we can declare constants using let kw.
• we can declare variables using var kw.
• we can declare multiple cons. or varls. on a single using commas,
• EX== 
• let kj=20 //constant 
• var dj=30 //variable 
• var x=3.4,y=43,z=43.4

    

• Swift assigns each variable and constant a type based on what value it’s given when it’s created. So, when you write code like this Swift can see it holds a string.
• let str = "Hello, playground"
• //That will make str a string, so you can’t try to assign it an integer or a boolean later on. This is called type inference: Swift is able to infer the type of something based on how you created it.

• 
  

IMPORTANT➖

If you want you can be explicit about the type of your data rather than relying on Swift’s type inference, like this:

var album: String 

let year: Int = 1989

let height: Double = 1.78

let TaylorRocks: Bool = true

//Notice that booleans have the short type name Bool, in the same way, that integers have the short type name Int.

//Strings start and end with double quotes, but if you want them to run across multiple lines you should use three sets of double-quotes.

/ex

var str1 = """

This goes

over multiple

lines

"""

//colon in the declaration means ".. type of .." code can be read as--  ##@ "Declare a variable Album as a string" //From the above example 

//now Without any error

album=“hello”

Integers hold whole numbers, doubles hold fractional numbers, and booleans hold true or false.

• String interpolation allows you to create strings from other variables and constants, placing their values inside your string.
• Swift uses type inference to assign each variable or constant a type, but you can provide explicit types if you want.

Constant and variable cannot contain whitespace characters, mathematical symbols, a private use Unicode scalar values, box or a line or box characters nor Cannot begin with a number

---

• string interpolation – the ability to place variables inside your strings to make them more useful.
• You can place any type of variable inside your string – all you have to do is write a backslash, \, followed by your variable name in parentheses

var score = 85
var str = "Your score was \\(score)"

• basic swift

  • step 1

    For commenting short cut is commend + /

    in swift programming language, we use camel casing ex - basicSwiftNotes (Here is the first letter is small and the starting of next to 2 letters are capital)

    To include something mathematical or some variable in between the print statement we have to keep \ and write our operations in ()

    print("text \(8403+903) text")== called string Interpolation

    print("hello \\(2+4) world")
    
    //op-
      //hello 5 world
    
    print("result of 5+3 = \\(5+3)")
    

• continues 

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