Swift index


文字列の一番始めを返す var startIndex: String.Index

var endIndex: String.Index A string’s “past the end” position—that is, the position one greater than the last valid subscript argument.

func formIndex(after: inout String.Index) Replaces the given index with its successor.

func index(before: String.Index) -> String.Index Returns the position immediately before the given index.

func formIndex(before: inout String.Index)