What is overloading in .net?

Whether to choose an array or a List depends on the scene. 1. Use arrays first when data is fixed, because the fixed-length feature is lighter, suitable for graphics processing, underlying API and other scenarios; 2. Use List when dynamic expansion or frequent addition and deletion, because it automatically expands and provides rich methods to improve development efficiency; 3. In terms of performance, array memory is more compact, List has management overhead but can be optimized through pre-allocated capacity; 4. The access speeds are similar, but the array does not support direct addition and deletion, and the inter-insertion efficiency of List is low. Just make reasonable choices based on the data volume, operating frequency and performance requirements.

Top-levelstatementsinC#9simplifycodeforsmallprogramsbyeliminatingtheneedforexplicitclassesandMainmethods.Theyallowdirectexecutionofcode,idealforscripts,learning,andprototyping.Youcanuseusingdirectives,declarevariables,useawait,andreturnexitcodes,butc

In C#, the main difference between value types and reference types is data storage and assignment behavior. 1. The value type directly stores data. When assigning, copy the value itself, such as int, float, struct and enum, modifying one variable does not affect the other; 2. The reference type stores references to the data, and copying the reference when assigning, such as class, interface and delegate, modifying one variable will affect the other; 3. The value type is usually stored on the stack, while the reference type object is allocated on the heap; 4. The value type cannot be null by default (unless the nullable type is used), and the reference type can be set to null; 5. Comparison of the actual value when comparing the value type, and compare the reference address when comparing the reference type (except

When handling file streams and I/O operations in C#, you need to master core classes and modes such as FileStream, StreamReader, asynchronous I/O and path processing. 1. Use FileStream to perform underlying file operations, support synchronization/asynchronous and access mode control, and use should ensure resource release and pay attention to FileMode and FileShare settings; 2. StreamReader and StreamWriter provide text read and write encapsulation, which is simpler and easier to use, can specify encoding methods, and can simplify one-time operations by File.ReadAllText() and other applications; 3. Asynchronous I/O improves responsiveness through async/await, suitable for large files or networks

When using var, it should be determined based on whether the type is clear and whether the readability is affected. 1. When the type is clear on the right side of the assignment, such as varlist=newList(); can improve the code simplicity; 2. When the type is fuzzy or returns to object or interface type, var should be avoided, such as IEnumerableresult=SomeMethod(); to improve readability; 3. Use var reasonably in anonymous types and LINQ queries, such as receiving anonymous objects, but subsequent processing is recommended to encapsulate it as a specific type; 4. In team projects, coding style should be unified, and var should be used reasonably through .editorconfig or code review to avoid abuse and affect maintenance.

Comparing strings in C# should be based on the scene selection method. The == operator is case-sensitive by default and compared based on the current culture, but is not suitable for complex scenarios. 1. Using the == operator is suitable for quick comparison, but may not meet the expected results due to culture or case; 2. Using String.Equals() and passing in StringComparison enumeration can achieve more precise control, such as Ordinal, OrdinalIgnoreCase, InvariantCulture, etc.; 3. Pay attention to handling null or empty strings when comparing. It is recommended to use the string.Equals() static method or use string.IsNullOrEmpt first.

The most common method of formatting DateTime objects into custom strings in C# is to use the ToString() method and pass in the format string, which includes: 1. Use standard format strings such as "d", "D", "t", and "T" to quickly implement common date and time formats; 2. Accurately control the output format through custom format strings such as "yyyy-MM-dd", "dd/MM/yyyyHH:mm"; 3. Use CultureInfo to handle format differences in different cultural environments to adapt to multilingual users.

The query syntax or method syntax of LINQ should be selected according to the scene. ① Query syntax is suitable for SQL-like expressions, such as multi-step filtering, projection, sorting, multi-table joining, grouping statistics, etc., with clear and intuitive structure; ② The method syntax is more flexible, supports chain calls and dynamic query conditions construction, and is suitable for aggregation functions, asynchronous operations and scenarios where splicing logic is required; ③ Some operations such as Take, Skip, Any, etc. can only use method syntax. The two functions are the same, and the choice mainly depends on personal habits and specific needs. Reasonable mixing of the two can improve the readability and maintenance of the code.