The NSRegularExpression class is used to represent and apply regular expressions to Unicode strings. An instance of this class is an immutable representation of a compiled regular expression pattern and various option flags. The pattern syntax currently supported is that specified by ICU. iOS 4.0+ macOS 10.7+
This class in the Apple developer library (Mac OS X, iOS) is used to represent and apply regular expressions to Unicode strings.
NOTE: This tag should be used only for questions specific to the NSRegularExpression class. Questions about regular expressions in general should be tagged regex.