Both the List.Find method and the Enumerable.FirstOrDefault method can be used to locate the first element that meets a
specified condition within a collection. However, for List objects, List.Find may offer superior performance compared to
Enumerable.FirstOrDefault. While the performance difference might be negligible for small collections, it can become significant for
larger collections. This observation also holds true for ImmutableList and arrays.
It is important to enable this rule with caution, as performance outcomes can vary significantly across different runtimes. Notably, the performance improvements in .NET 9 have brought
FirstOrDefault closer to the performance of collection-specific Find methods in most scenarios.
Applies to
What is the potential impact?
We measured at least 2x improvement in the execution time. For more details see the Benchmarks section from the More info
tab.
