What is array?

ArrayList is a dynamic array. You can add and remove the elements from an ArrayList at runtime. In the ArrayList, elements are not automatically sorted.

A collection works as a container for instances of other classes. All classes implement ICollection interface.

Interface is an abstract class that has only public abstract method. These methods only have declaration not the definition. These abstract methods must be implemented in the inherited classes.

Lock statement is used to ensure that one thread doesn't enter a critical section of code while another thread is in the critical section. If another thread attempts to enter a locked code it will wait, block, until the object is released.

If you want to transport an object through network then you have to convert the object into a stream of bytes. The process of converting an object into a stream of bytes is called serialization.

int m_PersonID = 0;  
public int PersonID  
{  
get { return m_PersonID; }  
set { m_PersonID = value; }  
}  

Early binding and late binding are the concept of polymorphism. There are two types of polymorphism in C#.

• Compile Time Polymorphism: It is also known as early binding.
• Run Time Polymorphism: It is also known as late binding or method overriding or dynamic polymorphism.

Following are the access modifiers generally used for accessibility:

• Public: If you define an attribute or method as public, it can be accessed from any code of the project.
• Private: A private defined attribute or method can be accessed by any code within the containing class only.
• Protected: If you define the method or attribute as protected it can be accessed by any method in the inherited classes and any method within the same class.
• Internal: If you define an attribute or a method as internal, it is restricted to classes within the current position assembly.
• Protected internal: If you define an attribute or method as protected internal, access is restricted to classes within the current project assembly or types derived from the containing class.

Abstract class can have abstract and concrete methods whereas interface has only abstract methods.

The dispose() method is explicitly called by user to free unmanaged resources such as files, database connections etc whereas finalize() method is implicitly called by garbage collector to free unmanaged resources like files, database connections etc.

The dispose() method belongs to IDisposable interface whereas finalize() method belongs the Object class.