numberOfCaptureGroups
Returns the number of capture groups in the regular expression.
Declaration
var numberOfCaptureGroups: Int { get }Discussion
A capture group consists of each possible match within a regular expression. Each capture group can then be used in a replacement template to insert that value into a replacement string.
This value puts a limit on the values of n for $n in templates, and it determines the number of ranges in the returned NSTextCheckingResult instances returned in the match... methods.
An exception will be generated if you attempt to access a result with an index value exceeding numberOfCaptureGroups``-1.