This document provides an introduction to strings, characters, and collection types like arrays, sets, and dictionaries in Swift. It demonstrates how to create, access, and modify these different data types through examples like string literals and interpolation, character iteration, array indexing and insertion, set membership testing, and dictionary lookups and updates.

1. Basic
Swift
Johnson

2. Introduction
• String and Characters
• Collection type

3. String Literals
Create a String
let a = "something"
var b = "something"
Create a empty String
var a = String() or ""

4. String Mutability
var a = "abc"
a += "def" // a = "abcdef"
let a = "abc"
a += "def" //constant String can't modify

5. Working with Characters
let someString = "abc"
for character in someString.characters
{ print(character) }
//a
//b
//c

6. Working with Characters
let Test: character = ["T", "e", "s", "t"]
let testString = String(Test)
//testString = Test

7. Concatenating Strings and
Characters
let appleString = "apple"
let penString = "pen"
let Uhnn = appleString + penString
//Uhnn = "applepen"

8. Concatenating Strings and
Characters
var appleString = "apple"
let penString = "pen"
appleString += penString
//appleString = "applepen"

9. String Interpolation
let multiplier = 3
let message =
"(multiplier) times 2.5 is (Double(multiplier) * 2.5)"
//message = 3 times 2.5 is 7.5

10. Special Characters in String
Literals
let wiseWords = ""Imagination is more important than knowledge" n- Einstein"
// "Imagination is more important than knowledge"
- Einstein
let dollarSign = "u{24}" // $, Unicode scalar U+0024

11. Extended Grapheme
Clusters
let combinedEAcute: Character = "u{65}u{301}"
// e followed bý
let decomposed: Character =
"u{1112}u{1161}u{11AB}"
// , ,

12. Counting Characters
let appleString = "apple"
print(appleString.charaters.count)
//print 5
let decomposed = "u{1112}u{1161}u{11AB}"
print(decomposed.charaters.count)
//print 1

13. Accessing and Modifying a
String
let apple = "apple"
apple[apple.startIndex]
//a
apple[apple.index(before: apple.endIndex)]
//e
apple[apple.index(after: apple.startIndex)]
//p
apple[apple.index(apple.startIndex, offsetBy: 3)]
//l

14. Inserting and Removing
var apple = "apple"
apple.insert("!", at: apple.endIndex)
//apple = apple!
apple.insert(contanceOf: "pen".characters, at:
apple.index(before: apple.endIndex))
//apple = applepen!

15. Inserting and Removing
apple.remove(at: apple.index(before:
apple.endIndex))
//applepen
apple.removeSubrange(apple.index(apple.endInd
ex, offsetBy: -4)..<apple.endIndex)
//appl

16. Comparing Strings
let apple = "apple"
let secondApple = "apple"
if apple == secondApple {
print("same")
}
//same

17. Prefix and Suffix Equality
To check whether a string has a particular string
prefix or suffix,
call the string’s hasPrefix(_:) and hasSuffix(_:)
methods,
both of which take a single argument of type String
and return a Boolean value.

18. Collection Types
• Array
• Set
• Dictionary

19. Array
Empty array
var empty = [type]()
empty = []
Default value
var something = Array(repeating: 0.0, count: 3)
//something = [0.0, 0.0, 0.0]

20. Array
Creating array with Array literal
var arrayName: [type] = [something1, something2]
var arrayName = [something1, something2]

21. Array
Accessing and Modifying an Array
.count
.isEmpty
.append(something)
array += [something1, something2]

22. Array
array[3...5] = ["else", "other"]
//then array[3,4] = "else", "other" , array[5] = nil
array.insert("some", at: 0)
//array[0] = "some"

23. Array
var catch = array[0]
//catch = first value in array
array[0] = "else"
//first in array = "else"

24. Array
for item in array{
print(item)
}
will print all value in array

25. Array
for (index, item) in array.enumerated() {
print(Index, item)
}
will print all index integer and value in array

26. Set
Empty set
let letSet = Set<type>()
Default set
let letSet: Set<type> = [Value1, Value2, Value3]
or
let letSet: Set = [Value1, Value2, Value3]

27. Set
Accessing and Modifying a Set
.insert(Value)
.count
.isEmpty
.remove(Value)
.contains(Value)
.sorted

28. Set
Fundamental Set Operations
.Union
.intersection
.symmetircDifference
.subtracting

29. Set
Fundamental Set Operations
.isSuperset(of: __)
.isSubset(of: __)
.isStrictSuperset(of: __)
.isStrictSubset(of: __)

30. Dictionary
Creating an Empty Dictionary
var letDictionary = [type(key): type(value)]()
Default value
var letDictionary = [key1: value1, key2: value2]

31. Dictionary
Accessing and Modifying a Dictionary
.count
.isEmpty
.updateValue(newValue, forKey: key)
.removeValue(forKey: key)

32. Dictionary
letDictionary[newKey] = newValue
letDictionary[key] = newValue

33. Dictionary
for (key, value) in letDictionary{
print("(key): (value)")
}
for key in letDictionary.keys{
print("(key): (value)")
}

34. Dictionary
for key in letDictionary.keys{
print(key)
}
for value in letDictionary.values{
print(value)
}

35. Dictionary
let letDictionary = ["XX": "AA","YY": "BB"]
let keyOfDictionary = [String](letDictionary.keys)
//keyOfDictionary is ["XX", "YY"]
let valueOfDictionary = [String](letDictionary.values)
//valueOfDictionary is ["AA", "BB"]