C # and. NE Study day 11th

1, the Richter conversion
1), subclasses can be assigned to the parent class
2), if the parent class is loaded with a subclass object, then it can be said that the parent class is strongly converted to a subclass object.

2.
A subclass object can call a member in the parent class, but the parent class object will always be able to invoke only its own members.

3.
is: Represents the type conversion, returns a true if the conversion succeeds, or returns a false
As: Represents a type conversion and returns the corresponding object if it can be converted, otherwise returns a null

4, Protected
Protected: can be accessed within the current class and within the subclass of the class.

5. Length of ArrayList set
When the number of elements actually contained in the collection (count) exceeds the number of elements that can be contained (capcity),
The collection will open up to one more space in memory to ensure that the length of the collection is always sufficient.

6, hastable key-value pairs dictionary sun Sun---Sun
In the set of key-value pairs, we are looking for values based on the key.
Key value pair Object [key]= value;
: The key must be unique in the set of key-value pairs, and the value can be repeated 7, the Foreach Loop

8. Encoding format
The reason for garbled is because you save this file in the same encoding format as the one you opened.

9. text File
Drag into the TXT file, but also can understand the file is a text file.

C # and. NE Study day 11th