Basic Operators

Nil-Coalescing Operator

The nil-coalescing operator (a ?? b) unwraps an optional a if it contains a value, or returns a default value b if a is nil.

The expression a is always of an optional type. The expression b must match the type that is stored inside a.

The nil-coalescing operator is shorthand for the code below:

a != nil ? a! : b

Range Operators

let count = 10
for i in 1...count {
}

for i in 1..<count {
}

One-Sided Ranges

for name in names[2...] {
    print(name)
}

for name in names[...2] {
    print(name)
}