C # basic learning (1)

 

Packing and unpacking

Boxing: A value type is implicitly converted to an object type, or converted to an interface-type applied to this value type ). bind a value of the value type, that is, create an object instance and give the value to the object.

Using System

Class test {

Public static void main (){

Int I = 10;

Object OBJ = I; // object type

If (obj is int ){

Console. Write ("the value of I is boxing ")

}

I = 20; // change the I value

Console. writeline ("int: I = {0}", I );

 

Console. writeline ("Object: OBJ = {0}", OBJ );

}

}

 

Output result:

The value of I is boxing

INT: I = 20;

Object: OBJ = 10;

It indicates that the value of the boxed type is assigned to the object as a copy.

Binning conversion.

An object type is explicitly converted to a value type, or an interface type is explicitly converted to a value type that executes the interface.

Int I = 10;

Object OBJ = I;

Int J = (INT) OBJ;