ROSLYN.PERFORMANCE.CA1841 : Prefer Dictionary.Contains methods (C#)

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ROSLYN.PERFORMANCE.CA1841 : Prefer Dictionary.Contains methods (C#)

Summary

'ContainsKey' is usually O(1), while 'Keys.Contains' may be O(n) in some cases. Additionally, many dictionary implementations lazily initialize the Keys collection to cut back on allocations.

This check corresponds to Roslyn rule CA1841. For full rule details, see the Microsoft website: CA1841.

Properties

Class Name	Prefer Dictionary.Contains methods (C#)
Significance	reliability
Mnemonic	ROSLYN.PERFORMANCE.CA1841
Categories	None
Availability	Available for C# only.
Enabling	Checks for this warning class are enabled by default. To disable them, add the following WARNING_FILTER rule to the project configuration file. WARNING_FILTER += discard class="Prefer Dictionary.Contains methods (C#)"

Relevant Configuration File Parameters

The following configuration file parameters affect checks for this warning class.