ReSharper 2017.3 Help

Code Inspection: Parameter type can be IEnumerable of T

If you have a method whose parameter is an array, a List, or some other type that implements IEnumerable<T>, ReSharper offers an option to change the parameter type to IEnumerable<T> — provided that the method itself only iterates the collection and does not access any non-IEnumerable members.

The benefit from this change is that the method becomes agnostic with respect to the type of the collection you pass to it.

Suboptimal codeAfter the quick-fix
private void ViewCategories(IList<string> categories) { foreach (var c in categories) { Console.WriteLine(c); } }
private void ViewCategories(IEnumerable<string> categories) { foreach (var c in categories) { Console.WriteLine(c); } }
Last modified: 7 December 2017

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