What are the differences between System.String and System.Text.StringBuilder classes? System.String: Immutable: Once created, the value cannot be changed. Performance: Creating a new string for every modification can be slower for frequent changes. Usage: Suitable for scenarios with infrequent or few string modifications. System.Text.StringBuilder: Mutable: Can be modified without creating a new instance. Performance: More efficient […]

The “protected internal” accessibility modifier in C# allows a member to be accessed by any code within the same assembly (internal) and by derived classes (protected) even if they are in different assemblies. This combines the features of both “protected” and “internal” access levels.

No, a private virtual method cannot be overridden. Only protected, internal, or public virtual methods can be overridden in derived classes because private methods are not accessible outside their own class.

An array holds items of the same type and has a fixed size. An ArrayList can hold items of different types and does not have a fixed size. Array: Fixed Size: Size is set at the time of creation and cannot be changed. Type-Safe: Stores elements of a specific type. Performance: Faster access due to […]

Method overloading in C# is the practice of defining multiple methods with the same name but different parameter lists within the same class. The differences can be in the number of parameters, types of parameters, or both. It allows methods to perform similar but slightly different tasks, improving code readability and usability.

Sealed classes in C# are classes that cannot be inherited by other classes. This is done using the sealed keyword. Sealing a class prevents it from being used as a base class, ensuring that its implementation remains unchanged and final. This can be useful for enhancing performance and maintaining security by preventing further subclassing.

Custom Controls: Produced as compiled code, easy to use, and can be added to the toolbox for drag-and-drop use in web forms. User Controls: Similar to ASP include files, easy to create but cannot be added to the toolbox or dragged and dropped from it.

A value type holds the data value directly within its own memory space. A reference type, on the other hand, stores the address of the memory location where the actual data is kept, essentially acting as a pointer to that data.

An interface class in C# is a contract that defines a set of methods, properties, events, or indexers that a class must implement. It does not contain any implementation itself, only the signatures. Implementing an interface ensures that a class provides specific functionality, allowing for a consistent API and enabling polymorphism.

Read-Only: Initialized at declaration or in the constructor. Can have different values at runtime. Constants: Initialized at declaration. Value is fixed and unchangeable. Key Difference: Read-only can be set at runtime, while constants are set at compile-time and cannot change.