What is Overriding?
Method overriding is a feature that allows to invoke functions (that have the same signatures) and that belong to different classes in the same hierarchy of inheritance using the base class reference. In C# it is done using keywords virtual and overrides .
Default Access modifiers in C#?
An enum has default modifier as public
A class has default modifiers as private . It can declare members (methods etc) with following access modifiers:
public
protected
internal
private
protected internal
An interface has default modifier as public
A struct has default modifier as private and it can declare its members (methods etc) with following access modifiers:
public
internal
private
A class has default modifiers as private . It can declare members (methods etc) with following access modifiers:
public
protected
internal
private
protected internal
An interface has default modifier as public
A struct has default modifier as private and it can declare its members (methods etc) with following access modifiers:
public
internal
private
- Can we specify the access modifier for explicitly implemented interface method?
No, we can't specify the access modifier for the explicitly implemented interface method. By default its scope will be internal.
- What is Protected Internal access modifier in C#?
Protected Internal is a access modifiers for the members (methods or functions) ie. you can't declare a class as protected internal explicitly. The members access is limited to the current assembly or types derived from the containing class.
Protected Internal means the method is accessible by anything that can access the protected method UNION with anything that can access the internal method.
Protected Internal means the method is accessible by anything that can access the protected method UNION with anything that can access the internal method.
What is Protected access modifier in C#?
The protected keyword is a member access modifier. It can only be used in a declaring a function or method not in the class ie. a class can't be declared as protected class.
A protected member is accessible from within the class in which it is declared, and from within any class derived from the class that declare this member. In other words access is limited to within the class definition and any class that inherits from the class
A protected member of a base class is accessible in a derived class only if the access takes place through the derived class type.
A protected member is accessible from within the class in which it is declared, and from within any class derived from the class that declare this member. In other words access is limited to within the class definition and any class that inherits from the class
A protected member of a base class is accessible in a derived class only if the access takes place through the derived class type.
What is Internal access modifier in C#?
The internal keyword is an access modifier for types and type members ie. we can declare a class as internal or its member as internal. Internal members are accessible only within files in the same assembly (.dll). In other words, access is limited exclusively to classes defined within the current project assembly.
What is Private access modifier in C#?
The private keyword is a member access modifier ie. we can't explicitly declare a class as Private, however if do not specify any access modifier to the class, its scope will be assumed as Private. Private access is the least permissive access level of all access modifiers.
Private members are accessible only within the body of the class or the struct in which they are declared. This is the default access modifier for the class declaration.
Private members are accessible only within the body of the class or the struct in which they are declared. This is the default access modifier for the class declaration.
What is Public access modifier in C#?
The public keyword is an access modifier for types and type members ie. we can declare a class or its member (functions or methods) as Public. There are no restrictions on accessing public members.
What is pure virtual function in OOP?
When you define only function prototype in a base class without and do the complete implementation in derived class. This base class is called abstract class and client wont able to instantiate an object using this base class.
A pure virtual function is a function that must be overridden in a derived class and need not be defined. A virtual function is declared to be "pure" using the curious "=0"
syntax:
class Base {
public:
void f1(); // not virtual
virtual void f2(); // virtual, not pure
virtual void f3() = 0; // pure virtual
};
When to Use Abstract Classes and When Interfaces.
If you anticipate creating multiple versions of your component, create an abstract class. Abstract classes provide a simple and easy way to version your components. By updating the base class, all inheriting classes are automatically updated with the change. Interfaces, on the other hand, cannot be changed once created. If a new version of an interface is required, you must create a whole new interface.
If the functionality you are creating will be useful across a wide range of disparate objects, use an interface. Abstract classes should be used primarily for objects that are closely related, whereas interfaces are best suited for providing common functionality to unrelated classes.
If you are designing small, concise bits of functionality, use interfaces. If you are designing large functional units, use an abstract class.
If you want to provide common, implemented functionality among all implementations of your component, use an abstract class. Abstract classes allow you to partially implement your class, whereas interfaces contain no implementation for any members.
A pure virtual function is a function that must be overridden in a derived class and need not be defined. A virtual function is declared to be "pure" using the curious "=0"
syntax:
class Base {
public:
void f1(); // not virtual
virtual void f2(); // virtual, not pure
virtual void f3() = 0; // pure virtual
};
When to Use Abstract Classes and When Interfaces.
If you anticipate creating multiple versions of your component, create an abstract class. Abstract classes provide a simple and easy way to version your components. By updating the base class, all inheriting classes are automatically updated with the change. Interfaces, on the other hand, cannot be changed once created. If a new version of an interface is required, you must create a whole new interface.
If the functionality you are creating will be useful across a wide range of disparate objects, use an interface. Abstract classes should be used primarily for objects that are closely related, whereas interfaces are best suited for providing common functionality to unrelated classes.
If you are designing small, concise bits of functionality, use interfaces. If you are designing large functional units, use an abstract class.
If you want to provide common, implemented functionality among all implementations of your component, use an abstract class. Abstract classes allow you to partially implement your class, whereas interfaces contain no implementation for any members.
What are Constructors?
Constructors are used for initializing the members of a class whenever an object is created with the default values for initialization.
If no constructor defined then the CLR will provide an implicit constructor which is called as Default Constructor.
A class can have any number of constructors provided they vary with the number of arguments that are passed, which is they should have different signatures.
Constructors do not return a value
Constructors can be overloaded
What are the various types of Constructor
Public : Accessible to All
Private: Those classes in which only static members are there and you don't want there objects to be created in any class.
Static: Used for initializing only the static members of the class. These will be invoked for the very first time the class is being loaded on the memory. They cannot accept any arguments. Static Constructors cannot have any access modifiers.
Intern: implementations of the abstract class to the assembly defining the class. A class containing an internal constructor cannot be instantiated outside of the assembly (Namespace).
and External.
If no constructor defined then the CLR will provide an implicit constructor which is called as Default Constructor.
A class can have any number of constructors provided they vary with the number of arguments that are passed, which is they should have different signatures.
Constructors do not return a value
Constructors can be overloaded
What are the various types of Constructor
Public : Accessible to All
Private: Those classes in which only static members are there and you don't want there objects to be created in any class.
Static: Used for initializing only the static members of the class. These will be invoked for the very first time the class is being loaded on the memory. They cannot accept any arguments. Static Constructors cannot have any access modifiers.
Intern: implementations of the abstract class to the assembly defining the class. A class containing an internal constructor cannot be instantiated outside of the assembly (Namespace).
and External.
25 Aug 2013
0 comments:
Post a Comment