width(_:)

Declaration

static func width(_ x: Unicode.Scalar) -> Int

Parameters

• x:

  A Unicode scalar value.

Return Value

The width of x when encoded in UTF-8, from 1 to 4.

Discussion

Because a Unicode scalar value can require up to 21 bits to store its value, some Unicode scalars are represented in UTF-8 by a sequence of up to 4 code units. The first code unit is designated a lead byte and the rest are continuation bytes.

let anA: Unicode.Scalar = "A"
print(anA.value)
// Prints "65"
print(UTF8.width(anA))
// Prints "1"

let anApple: Unicode.Scalar = "🍎"
print(anApple.value)
// Prints "127822"
print(UTF8.width(anApple))
// Prints "4"