René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Rule request: AvoidArrayList","articleBody":"Aside from the [important remark](https://learn.microsoft.com/en-us/dotnet/api/system.collections.arraylist#remarks):\n\n\u003e [!Important]\n\u003e\n\u003e We don't recommend that you use the ArrayList class for new development. Instead, we recommend that you use the generic [List\u003cT\u003e](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.list-1?view=net-6.0) class. The [ArrayList](https://learn.microsoft.com/en-us/dotnet/api/system.collections.arraylist?view=net-6.0) class is designed to hold heterogeneous collections of objects. However, it does not always offer the best performance. Instead, we recommend the following:\n\u003e \n\u003e For a heterogeneous collection of objects, use the `List\u003cObject\u003e` (in C#) or List(Of Object) (in Visual Basic) type.\n\u003e For a homogeneous collection of objects, use the [`List\u003cT\u003e`](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.list-1?view=net-6.0) class. See [Performance Considerations](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.list-1?view=net-6.0#performance-considerations) in the [List\u003cT\u003e](https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.list-1?view=net-6.0) reference topic for a discussion of the relative performance of these classes. See [Non-generic collections shouldn't be used](https://github.com/dotnet/platform-compat/blob/master/docs/DE0006.md) on GitHub for general information on the use of generic instead of non-generic collection types.\n\nThe `ArrayList.Add` method returns an index of the added element which often unintendedly pollutes the PowerShell pipeline and causes unexpected issues, see e.g.: \n* [Powershell ArrayList magically inserts a zero [duplicate]](https://stackoverflow.com/questions/52641400/powershell-arraylist-magically-inserts-a-zero)\n* [Unexpected array size [duplicate]](https://stackoverflow.com/questions/58604984/unexpected-array-size)\n\nNote that [an `ArrayList` is not typesafe](https://stackoverflow.com/a/17984540/1701026) which is consistent with PowerShell as a loosely language.\nAlternatives for a `ArrayList` type are:\n* `[object[]]` which is also loosely *but not sizable*, or\n* `[System.Collections.Generic.List[Object]]` with is both sizable and loosely.","author":{"url":"https://github.com/iRon7","@type":"Person","name":"iRon7"},"datePublished":"2025-12-18T15:26:23.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/2147/PSScriptAnalyzer/issues/2147"}