Cover variables, types, array, condition, function
let
var
let i = 42 // An Int type let s = "hello" // A String type let s2: String = "Declare with explicit type"
class
struct
struct Person { let name: String let birthYear: Int } let alice = Person(...) // alice is an instance
if-let-else
switch-case
while
for item in array
for i in 0..<10
func isEven(num: Int) -> Bool { ... }
(Int) -> Bool