iOS Developer Library


Foundation Framework Reference NSMutableCharacterSet Class Reference

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The NSMutableCharacterSet class declares the programmatic interface to objects that manage a modifiable set of Unicode characters. You can add or remove characters from a mutable character set as numeric values in NSRange structures or as character values in strings, combine character sets by union or intersection, and invert a character set.

Mutable character sets are less efficient to use than immutable character sets. If you don’t need to change a character set after creating it, create an immutable copy with copy and use that.

NSMutableCharacterSet defines no primitive methods. Subclasses must implement all methods declared by this class in addition to the primitives of NSCharacterSet. They must also implement mutableCopyWithZone:.

NSMutableCharacterSet is “toll-free bridged” with its Core Foundation counterpart, CFMutableCharacterSetRef. See Toll-Free Bridging for more information.

  • Replaces all the characters in the receiver with all the characters it didn’t previously contain.



    func invert()


    - (void)invert


    Inverting a mutable character set, whether by invert or by invertedSet, is much less efficient than inverting an immutable character set with invertedSet.


    Available in iOS 2.0 and later.

    See Also

    – invertedSet (NSCharacterSet)