C# 程式設計/關鍵字/when

在 catch 語句或 switch 語句的 case 標籤中，when 上下文關鍵字用於提供過濾功能。該關鍵字緊接在條件之前，例如 when (lifeValue < 1)。

C# 關鍵字
abstract as base bool break byte case catch char checked class const continue decimal default delegate do double else enum event explicit extern false finally fixed float for foreach goto if implicit in int interface internal is lock long namespace new null object operator out override params private protected public readonly ref return sbyte sealed short sizeof stackalloc static string struct switch this throw true try typeof uint ulong unchecked unsafe ushort using var virtual void volatile while
特殊的 C# 識別符號（上下文關鍵字）
add alias async await dynamic get global nameof partial remove set value when where yield
上下文關鍵字（用於查詢）
ascending by descending equals from group in into join let on orderby select where