. NET Software Engineer Interview Summary (1)

In fact, for fresh graduates interview, if your actual combat experience is insufficient, the interviewer will generally ask some basic questions. (This blog content answer is summed up some of the original author's knowledge,)

1 . Differences between interfaces and abstract classes (from:http://www.cnblogs.com/huihui-gohay/archive/2009/12/13/1623070.html#undefined)

The difference between an abstract class and an interface is the use of motivation. Abstract classes are used for reuse of code, and the motivation for using interfaces is to achieve polymorphism.

Extended:

interface, on the surface there are several methods that do not have the body code definition composed of the collective body, there is a unique name, can be implemented by the class and interface (inheritance), the general form is

Interface Interface1

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void method1{}

void Method2{int Para1}

void method1{string para2, int para3}

｝

An interface is a set of rules that specify a set of rules that a class or interface that implements this interface must have. Embodies the nature "if you are ... You must be able to ... "the idea.

an interface is an abstract representation of a similar thing on a certain granularity view. Note that the emphasis here is on a certain granularity view, because the concept of "homogeneous things" is relative, and it differs because of the granularity of the view.

Lenovo to interface-oriented programming and object-oriented programming, what are the two differences between them?

interface-oriented programming: In the system analysis and architecture, distinguish between hierarchy and dependency, each level is not directly to its upper layer to provide services (that is, not directly instantiated in the upper layer), but by defining a set of interfaces, only to the upper layer exposed its interface function, the upper layer of the lower layer is only interface dependence, Rather than relying on specific classes.

interface-oriented programming and object-oriented programming are not lateral, it is not an independent programming idea that is more advanced than object-oriented programming, but is attached to the object-oriented ideology, which belongs to its part. Or, it is one of the essence of thought in object-oriented programming system.

2, SQL internal connection, left connection, right connection, outer connection, natural connection (from:http://www.blogjava.net/zolly/archive/2007/10/23/sqljion.html)

[1] Outer connection: Includes left connection, right connection (left outer connection and right outer connection) and full connection

(1) The result set of the left outer join includes all rows of the left table specified in the OUTER clause, not just the rows that match the joined columns. If a row in the left table does not have a matching row in the right table, all select list columns in the right table in the associated result set row are null (NULL).

(2) A right outer join is a reverse join of a left outer join. All rows of the right table will be returned. If a row in the right table does not have a matching row in the left table, a null value will be returned for left table.

(3) A full outer join returns all rows from the left and right tables. When a row does not have a matching row in another table, the selection list column for the other table contains a null value. If there are matching rows between the tables, the entire result set row contains the data values of the base table.

[2] Inner connection: Includes natural connection and equivalent connection

Inner joins use comparison operators to match rows in two tables based on the values of the columns that are common to each table

[3] Cross Connection
Cross join returns all rows from the left table, with each row in the left table combined with all rows in the right table

3. Benefits of the. NET Framework 4.0

http://www.cnblogs.com/ATree/archive/2010/05/28/net-framework-new-features.html

Also need to understand ...

4. WCF

Windows Communication Foundation (WCF) is a set of data communication application development interfaces developed by Microsoft, which can be translated as a Windows communication interface and it is. NET Framework is part of the. Introduced by the. NET Framework 3.0.

The ultimate goal of WCF is to send and receive messages between customers and services through a process or a different system, through a local network, or over the Internet.

WCF incorporates the capabilities of Web services,. NET Remoting, Message Queuing, and enterprise services and integrates them in Visual Studio.

WCF is dedicated to service-oriented development

from:http://www.cnblogs.com/iamlilinfeng/archive/2012/09/25/2700049.html

5. Rewriting, object-oriented

encapsulation, inheritance, polymorphism

(1) encapsulation, that is, to encapsulate objective things into abstract classes, and classes can put their own data and methods only trusted class or object operation, to the untrusted information hiding. Encapsulation is one of the object-oriented features and the main feature of object and class concept

(2) polymorphism (POLYMORPHISN) is a technique that allows you to set the parent object to be equal to one or more of his child objects, after which the parent object can operate differently depending on the attributes of the child object currently assigned to it. To put it simply, it is a sentence: A pointer to the parent class type is allowed to be assigned a pointer to the child class type.

Achieve polymorphism, there are two ways to overwrite, overload

(3) inheritance refers to the ability to use all the functions of an existing class and to extend these functions without rewriting the original class.

New classes created through inheritance are called "subclasses" or "derived classes."

The inherited class is called the base class, the parent class, or the superclass.

The process of inheritance is from the general to the special process.

To implement inheritance, it can be implemented through inheritance (inheritance) and combination (composition).

Inheritance concepts are implemented in three categories: implementation inheritance, interface inheritance, and visual inheritance.

• • Implementation inheritance refers to the ability to use the properties and methods of a base class without additional coding;
  • Interface inheritance refers to the ability to use only the names of properties and methods, but subclasses must provide the implementation;
  • Visual inheritance is the ability of a subform (class) to use the appearance of a base form (class) and to implement code.

from:http://blog.csdn.net/ma1kong/article/details/4457044

6, WebService security access, Access volume concurrency

7, class static non-static

8. Business

9. Index

10. Linq

11, stored procedures, data logic business logic

12. Value type, reference type what type string is

(due to the time problem follow up!!!!) )

. NET Software Engineer Interview Summary (1)