C# How to update and add data to Excel table using Ado.Net

C#.NET interview questions and answers include basic knowledge, core concepts, and advanced usage. 1) Basic knowledge: C# is an object-oriented language developed by Microsoft and is mainly used in the .NET framework. 2) Core concepts: Delegation and events allow dynamic binding methods, and LINQ provides powerful query functions. 3) Advanced usage: Asynchronous programming improves responsiveness, and expression trees are used for dynamic code construction.

C# is a modern, object-oriented programming language developed by Microsoft and as part of the .NET framework. 1.C# supports object-oriented programming (OOP), including encapsulation, inheritance and polymorphism. 2. Asynchronous programming in C# is implemented through async and await keywords to improve application responsiveness. 3. Use LINQ to process data collections concisely. 4. Common errors include null reference exceptions and index out-of-range exceptions. Debugging skills include using a debugger and exception handling. 5. Performance optimization includes using StringBuilder and avoiding unnecessary packing and unboxing.

Testing strategies for C#.NET applications include unit testing, integration testing, and end-to-end testing. 1. Unit testing ensures that the minimum unit of the code works independently, using the MSTest, NUnit or xUnit framework. 2. Integrated tests verify the functions of multiple units combined, commonly used simulated data and external services. 3. End-to-end testing simulates the user's complete operation process, and Selenium is usually used for automated testing.

C#.NETisversatileforbothwebanddesktopdevelopment.1)Forweb,useASP.NETfordynamicapplications.2)Fordesktop,employWindowsFormsorWPFforrichinterfaces.3)UseXamarinforcross-platformdevelopment,enablingcodesharingacrossWindows,macOS,Linux,andmobiledevices.

C#.NET is still important because it provides powerful tools and libraries that support multiple application development. 1) C# combines .NET framework to make development efficient and convenient. 2) C#'s type safety and garbage collection mechanism enhance its advantages. 3) .NET provides a cross-platform running environment and rich APIs, improving development flexibility.

Interview with C# senior developer requires mastering core knowledge such as asynchronous programming, LINQ, and internal working principles of .NET frameworks. 1. Asynchronous programming simplifies operations through async and await to improve application responsiveness. 2.LINQ operates data in SQL style and pay attention to performance. 3. The CLR of the NET framework manages memory, and garbage collection needs to be used with caution.

C#.NETissuitableforenterprise-levelapplicationswithintheMicrosoftecosystemduetoitsstrongtyping,richlibraries,androbustperformance.However,itmaynotbeidealforcross-platformdevelopmentorwhenrawspeediscritical,wherelanguageslikeRustorGomightbepreferable.

C# is widely used in enterprise-level applications, game development, mobile applications and web development. 1) In enterprise-level applications, C# is often used for ASP.NETCore to develop WebAPI. 2) In game development, C# is combined with the Unity engine to realize role control and other functions. 3) C# supports polymorphism and asynchronous programming to improve code flexibility and application performance.