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# Foundation Constants

This document defines constants in the Foundation framework that are not associated with a particular class.

## Topics

### Constants

[`NSAverageKeyValueOperator`](/documentation/Foundation/NSKeyValueOperator/averageKeyValueOperator)

The @avg array operator.

[`NSCountKeyValueOperator`](/documentation/Foundation/NSKeyValueOperator/countKeyValueOperator)

The @count array operator.

[`NSDistinctUnionOfArraysKeyValueOperator`](/documentation/Foundation/NSKeyValueOperator/distinctUnionOfArraysKeyValueOperator)

The @distinctUnionOfArrays array operator.

[`NSDistinctUnionOfObjectsKeyValueOperator`](/documentation/Foundation/NSKeyValueOperator/distinctUnionOfObjectsKeyValueOperator)

The @distinctUnionOfObjects array operator.

[`NSDistinctUnionOfSetsKeyValueOperator`](/documentation/Foundation/NSKeyValueOperator/distinctUnionOfSetsKeyValueOperator)

The @distinctUnionOfSets array operator.

[`NSFileProtectionCompleteWhenUserInactive`](/documentation/Foundation/FileProtectionType/completeWhenUserInactive)

[`NSInflectionConceptsKey`](/documentation/Foundation/NSAttributedStringFormattingContextKey/inflectionConceptsKey)

A key for the inflection concepts in the formatting context dictionary.

[`NSMaximumKeyValueOperator`](/documentation/Foundation/NSKeyValueOperator/maximumKeyValueOperator)

The @max array operator.

[`NSMinimumKeyValueOperator`](/documentation/Foundation/NSKeyValueOperator/minimumKeyValueOperator)

The @min array operator.

[`NSOperationNotSupportedForKeyException`](/documentation/Foundation/NSOperationNotSupportedForKeyException)

[`NSProgressFileOperationKindDuplicating`](/documentation/Foundation/Progress/FileOperationKind-swift.struct/duplicating)

[`NSSumKeyValueOperator`](/documentation/Foundation/NSKeyValueOperator/sumKeyValueOperator)

The @sum array operator.

[`NSUnionOfArraysKeyValueOperator`](/documentation/Foundation/NSKeyValueOperator/unionOfArraysKeyValueOperator)

The @unionOfArrays array operator.

[`NSUnionOfObjectsKeyValueOperator`](/documentation/Foundation/NSKeyValueOperator/unionOfObjectsKeyValueOperator)

The @unionOfObjects array operator.

[`NSUnionOfSetsKeyValueOperator`](/documentation/Foundation/NSKeyValueOperator/unionOfSetsKeyValueOperator)

The @unionOfSets array operator.

[`NSURLSessionUploadTaskResumeData`](/documentation/Foundation/NSURLSessionUploadTaskResumeData)

Key in the userInfo dictionary of an NSError received during a failed upload.


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