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Foundation Framework Reference NSMutableIndexSet Class Reference

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NSMutableIndexSet

The NSMutableIndexSet class represents a mutable collection of unique unsigned integers, known as indexes because of the way they are used. This collection is referred to as a mutable index set. The set of valid indexes are 0 .. NSNotFound - 1; trying to use indexes outside this range is an error.

The values in a mutable index set are always sorted, so the order in which values are added is irrelevant.

You must not subclass the NSMutableIndexSet class.

  • Shifts a group of indexes to the left or the right within the receiver.

    Declaration

    Swift

    func shiftIndexesStartingAtIndex(_ index: Int, by delta: Int)

    Objective-C

    - (void)shiftIndexesStartingAtIndex:(NSUInteger)startIndex by:(NSInteger)delta

    Parameters

    startIndex

    Head of the group of indexes to shift.

    delta

    Amount and direction of the shift. Positive integers shift the indexes to the right. Negative integers shift the indexes to the left.

    Discussion

    The group of indexes shifted is made up by startIndex and the indexes that follow it in the set.

    A left shift deletes the indexes in a range the length of delta preceding startIndex from the set.

    A right shift inserts empty space in the range (startIndex,delta) in the receiver.

    The resulting indexes must all be in the range 0 .. NSNotFound - 1.

    Availability

    Available in OS X v10.3 and later.