replacementIndex
The replacement position associated with a format string specifier.
Declaration
static let replacementIndex: NSAttributedString.KeyDiscussion
When creating an attributed string from a format string and one or more replacement values, this attribute indicates the ordinal index of each replacement. You must specify the NSAttributedStringFormattingApplyReplacementIndexAttribute option at creation time to add this attribute to the substituted text. The value of this key is an NSNumber with the replacement position of the substitute text.