NSScreencast Episode #125 Swift Basics

Swift Basics - NSScreencast

• swift
  • not intended to be replacement of objective-c
  • under NDA
• repl
  • var x = 30
    • no semicolon
  • let y = 50
    • constants
  • var count: Int
    • # count: Int: 0
    • all variable initialized by default value
  • var letter: Character = "A"
    • same as string
• array
  • var ids: Int[]
    • ids += 1
    • ids += [5,6,7]
    • ids [1,5,6,7]
  • let array => size never change
    • constantsでも中の要素は変わる
    • not immutable
• range
  • numbers[0..4]
    • not include 1,2,3,4
  • numbers[0...4]
    • include 1,2,3,4,5
  • opposite of Ruby
• Dictionary
  • separate by colon
  • square bracket
  • var gradebook = [ "Al": "A", "Joe": "B", "Charlie": "D" ]
    • Dictionary<String, String>
  • String?
    • question mark => this value might contain nil
    • force nil check
  • if grade { }
  • grades += grade
    • error: String? not unwrapped
    • unwrapp (!)
      • grades += grade!
  • if let grade =
    • without bang!
• loop
  • for (student, grade) in gradebook {}
• string interpolation
  • " (grade)"