C # Object-oriented fragmented knowledge points

Obgect:

All data types are obgect types;

Universal type var: the original variable is unchanged and replaced with Var;

Dynamic type: Like object, traversal needs to go;

is as:

type conversion operators;

(Type) object: Cast, if the conversion is unsuccessful, there will be an exception;

ArrayList arr = new ArrayList ();

Arr. ADD ();

foreach (Obgect o in arr)

{

If (O is Random)

{

Random r = (random) o;

Console.WriteLine (R.next (1,11));

}

}

is to determine whether an object or variable is a type that returns a bool;

ArrayList arr = new ArrayList ();

Arr. ADD ();

foreach (Obgect o in arr)

{

Random r = o as Random;

if (r! = null)

Console.WriteLine (R.next (1,11));

}

As type conversion if an object can be converted to a type, then he will convert;

If it cannot be converted to a type, NULL is returned and no error is made;

Universal variable var

Dynamically typed dynamic

generic type <t>:
Generic collection

Fixed type, not fixed length;

List<int> ABC = new list<int>;

Abc. Count ();

Class Library:

Commissioned:

Delegate

C # Object-oriented fragmented knowledge points