C # Basic Class notes

1, static and non-static difference: whether there is static

Non-static:

1) in a non-static class, you can have either an instance member or a static member

2) in the invocation instance member, through the object. Instance members

When a static member is called, the class name is passed. Static Members

Static:

1) Static classes can only have static members, cannot have instance members

2) A static class cannot be instantiated, that is, the object cannot be created

Summary: Static members must be called using the class name, and instance members use objects to invoke

Only static members can be accessed in a static function, and access to instance members is not allowed

Instance methods can access both instance members and static members

Use of static classes:

1) If you want your class to be a "tool class", consider writing a static

2) Static classes share resources throughout the project

Freeing Resources (Gc,garbage Collection garbage Collector): Static classes can release resources only after the program has finished all

2. Constructor function

Definition: The construction method is used to create the object, and the object can be initialized in the constructor. Reduced redundancy of the code

Role: Helps us initialize the object (assigning values to each property of the object in turn)

A constructor is a special method:

1) No return value, no write void

2) The constructor name must be the same as the class name

Public Student () {}

The access modifier for the constructor must be public

Constructor execution: The constructor executes when the object is created

Constructors can be overloaded (with the same function name, with different parameters)

There is a default parameterless constructor in the class, and when you write a new constructor, whether it is a parameter or a parameter, the default is eliminated.

3. New keyword

New has done three things for us:

1) opens up a space in memory

2) Create objects in the open space

3) Call the object's constructor to initialize the object-so the constructor's access modifier must be public

4. This keyword

Effect: 1) Represents the object of the current class this. Name=name;

2) The constructor for this class is explicitly called in the class public Student (string name,int age,char gender): This (name,0,gender)//Call the name and gender of this class constructor

5. destructor

Syntax: ~student () {function Body}

Function: When the program ends, the destructor executes, releasing the resource

C # Basic Class notes