Swift Basics

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Swift Basics

Constants

let height = 1.75
 
// Can't change later.

Variables

var health = 10
// Start with lower letters
 
// You can assign many variables in one line
var height = 10, breadth = 15, width = 20

Constants and Variables can use any character, even chinese or an emoji.

Annotations (don’t have to)

var health: Integer
var health, mana: Integer
// Annotating the TYPE
 
/* Types are:
- String
- Int
- Double
- Bool
- [other types] //Array
*/
 
// Need to indicate during function making.
// Don't need to indicate during normal usage. Because the system will infer what data type it is by what you inserted.

Printing

var health = 10
print("Your health is \(health)")
 
// Swift's version of an f-string

Ranges

a...b = a to b, inclusive
a..<b = a to b, exclusive
a...  = a onwards
 ...b = until b

Logical operators

!a       (not)
a && b   (and)
a || b   (or)

State properties

@State var playerCard = "card2"
 
// You need to add a @State to indicate properties that are SPECIAL because they affect the user interface.

Conditional statements

if a > b {
  // code
}
else if {
  // code
}

Arrays

var list = ["a", "b", "c"]
 
var list:[String] = ["a", "b", "c"]
 
list[0] = "n"
print(list)
>> ["n", "b", "c"]
 
// If using a structure
var menuItems:[MenuItem] = [firstItem, secondItem, thirdItem]

Random

random(in: 2...14)

Comments

// Comment
 
/* Comment over
two lines */

Semicolons

var health = 10 ; let name = "Elkan"
 
// Semicolons lets you combine 2 lines of code

Floating point numbers

  • Double: 64-bit FPN (min. 15dp) — used by default
  • Float: 32-bit FPN (min. 6dp)

Exponent

var exponent = 1.25e2
>> 1.25 x 10^2

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