tailieunhanh - The System.Object Class

Các Class Một trong những loại tài liệu tham khảo quan trọng nhất trong NET Framework. Là lớp Object trong namespace System. Để đánh giá đầy đủ ý nghĩa của lớp yêu cầu bạn hiểu thừa kế | The Class One of the most important reference types in the .NET Framework is the Object class in the System namespace. To fully appreciate the significance of the class requires that you understand inheritance which is described in Chapter 12 Working with Inheritance. For the time being simply accept that all classes are specialized types of and that you can use to create a variable that can refer to any reference type. is such an important class that C provides the object keyword as an alias for . In your code you can use object or you can write they mean exactly the same thing. TIP Use the object keyword in preference to . It s more direct and it s also consistent with using other keywords that have longer synonyms as you ll discover in Chapter 9 Creating Value Types with Enumerations and Structs. If your program contains a using System directive you could also write Object with a capital O without the System. prefix but it s best to consistently use the simpler keyword object. In the following example the variables c and o both refer to the same Circle object. The fact that the type of c is Circle and the type of o is object the alias for in effect provides two different views of the same object Circle c c new Circle 42 object o o c