JAYARAM. Department of Information Technology QUESTION BANK UNIT I BASICS OF C# Integer real single character string

Transcription

1 Estd: 1994 JAYARAM COLLEGE OF ENGINEERING AND TECHNOLOGY Pagalavadi, Tiruchirappalli (An approved by AICTE and Affiliated to Anna University) ISO 9001:2000 Certified Department of Information Technology QUESTION BANK UNIT I BASICS OF C# 1. What is literal? Literal are value constants assigned to variables or results of expression in a program.c# support several type of literals as, C# literals Numeric Boolean character Integer real single character string 2. What is constant? The variables whose values do not change during the execution of a program such as variables can be made unmodifiable by using the constant keyword while initializing then, Const int Rows=19; Const int cols=20; Const int Num=30;

2 3. What is a variable? A variable is an identifier that denotes a storage location used to store a data value, a variable may take different values at different times during the execution of the program. Eg: average, height 4. How are literals and variables are important in developing a program? Variable names may consist of alphabets digits and the underscore (_).subject to the following conditions They must not begin with a digit uppercase and lowercase are distinct. White space is not allowed. Variable names can be any length. 5. Why do we need to use constants in a program? They make our program easier to read out understand. They make our program easier to modify and minimize accidental errors like attempting to assign values to same variables which are expected to be constants. 6. List the two predefined reference types? Object type String type 7. What is local variable? Variables declared inside methods are called local variables. They are not available for use outside the method definition. 8. What do you mean by scope? The scope of the variable in the region of code within which the variable can be accessed. This depends on the type of the variable and pace of its declarations C# defines several categories of variables. They include Static variables Instant variables Array elements Value parameters Output parameters Local variables

3 9. State the scope of following variables? Local variables: Local variables can also be declared inside the program blocks that are defined between an opening brace { and a closing brace } Field variables: Static and instant variables are declared at the class level and are known as fields or field variables. Method parameters: The variables x,y and z are parameters of the method func().the value parameters x will exist til the end of the method. 10. What is initialization? Why it is necessary? The process of giving initial values to variables is known as initialization if any variables are not provided with initial values, the c# compiler will generate errors. 11. What are the application of backslash character literals? CHARACTER \a \b \f \n \r MEANING alert backspace form feed new line carriage return 12. How do the value type differ from reference type in term storage? The value type the size of the value that can be stored depends on the data type. In reference type the string literals can be stored in string object as values. 13. State the rules that govern the naming of variables? They must not begin with a digit. It should not be a keyword. White space is not allowed. variables names can be of any length. 14.What does a declaration of the variable accomplish?

4 Declaration does three things: It tells the compiler what the variables name is. It specify what type of data the variable will hold. The place of declaration decides the scope of the variables. 15. What are the invalid literals among the following invalid literals and why? Rs character would not given with decimal values(or)digits e(+4)- The exponent is a integer it is cannot be given with open close brace() commas non-digits characters not allowed between digits. 16. Which of the following are invalid variables name and why? First name The only underscore is allowed, other symbols not allowed. 3 rd Row Variables must not begin with digits Sum Total Whitespace is not allowed Float Variables should not be allowed Total_marks Expert underscore other symbols is not used. 17. What is boxing? Why do we do it? The object oriented programming, methods are invoked using objects. Since the value type such as int and long are not object. We cannot use them to call members c# enables us to achieve this through a technique known as boxing. 18. What is unboxing? How it is achieved? Unboxing is the process of converting the objects type back to the value type. When performing unboxing c# checks that the value type we request is actually stored in the object under conversion. Only if it is unboxed. 19. What do you mean by default values? The variable is either explicitly assigned a value or automatically assigned a default value. The following categories of variables are automatically initialized to their default values Static variables Instance variables Array elements

5 20. State default values of the following objects: Char type = \x000 Decimal type = 0.0m Bool type = false Class type = 0 PART-B 1. Explain the following i. For each ii. Structures iii. Arrays iv. Array list 2. i. Describe the characteristic of.net architecture. ii. Write in detail about Common Langage Runtime 3. i Develop a program that uses a method to sort an array of integers? ii Write a program for preparing student-marklist 4. iwrite a program for inventory system using structures.. ii Find whether a no. is prime or not. 5. i. Explain the execution model of the.net framework ii Describe the components of the.net framework and explain the features of each component 6. i List out the various value and reference types supported in C# iiwhat is a jagged array? Explain its use with simple example.

6 1.Define classes and objects OBJECT ORIENTED ASPECTS OF C# C# is a true object oriented language and therefore the underlying structure of all c# programs is classes. Anything we wish to represent in a c3 program must be encapsulated in a class that defines the state and behavior of the basic program component are objects. 2.What are the basic principles of OOP? Encapsulation Inheritance Polymorphism 3.What is defining a class? Class definition: { Class classname { [variable declaration;] [methods declaration;] } 4.What is adding variables in classes and objects? Class rectangle { int length; int width; } 5.What is adding methods in class and objects? Type methodname(parameter-list0 { method-body; } 6.What are the member access modifiers? Private Public

7 Protected Internal Protected internal 7.How objects are created? Creating an objects is also known as the instancing of the objects. Objects in c# are created using new operator. 8.Define constructor. The more simpler and concise to initialize an object when it is first created. c# supports a special type of method, called constructor, that enables to an object to initialize itself when it is created. 9.What are the types of constructor? Static constructor Private constructor Copy constructor 10.Define destructor A destructor is opposite to constructor. It is method called when an object is no more required. Eg: class fun {. -fun() { } } 11. Define inheritancethe mechanism of designing or constructing one class from other class is called inheritance. It may be achieved in two forms. Classical form Containment form

8 12. Define polymorphism Related to inheritance an equally important feature is polymorphism. This feature permits the same method to be used for the different operations in different derived class. 13. How to define a subclass Subclass is defined as Class subclass-name: base class-name { Variables declarations; Methods declarations; } 14. Define operation polymorphism Operation polymorphism is implemented using the overload methods and operators, and this is processed by selected for the invoking process. 15. Define inclusion polymorphism Inclusion polymorphism is achieved through the use of virtual functions. 16. Define interface An interface can contain one or more methods, properties, indexes and events but none of them are implemented in the interface itself. 17. Write the syntax for the interface Interface Name { Member declarations; } 18. Define operator overloading Operator overloading is one of the many existing feature of the object oriented programming

9 Eg: Vector u1, u2,u3;.... u3=u1+u2; Vector-> class or struct u1,u2-> added to get u3 vector 19.What are the types of the errors Two types of the errors Compile-time error Run-time error 20.Define exception An exception is a condition caused by a run time error in the program. Eg: Division by 0 21.Define error handling code mechanism Find the problem Inform that the error has occurred Receive the error information Take corrective action 22.How exceptions are used for debugging Exception handling mechanism may be effectively used to locate the type and the place of the errors. Once we identify the errors, try to find out why these errors occur before cover with exception handling. 23.Define delegates. In general delegates means a person acting for another person. Creating the delegates involve the 4 steps Delegate declarations Delegate method definition

10 Delegate instantiation Delegate invocation 24.What is delegate declaration? A delegate declaration is a type declaration and takes the following general form: Modifier delegate return-type delegate-name(parameters); 25.What is delegate method? The methods whose references are encapsulated into a delegate instance are known as the delegate methods callable entities PART-B 1. Explain creating and using delegates with example 2. Discuss about inheritance and polymorphism in detail. 3.. List out the exception handling statements supported in C# and explain with example. 4. i.consider a class which stores a distance value which stores kilometer and meter.overload the + operator to add two distance objects. ii. Elucidate events and implement event handler 5. Implement and explain the following type of inheritance with a suitable example. A B C

11 UNIT III APPLICATION DEVELOPMENT ON.NET PART-A 1. List out the general properties of control. The controls you add to a form have something called Properties. A property of a control is things like its Height, its Width, its Name, its Text, and a whole lot more besides. To see what properties are available for a button, make sure the button is selected. If a control is selected, it will have white squares surrounding it. If your button is not selected, simply click it once. 2. What is the use of scrollable control? It adds the ability for window to display and handle vertical and horizontal scrollbars used to scroll the client area of the window. 3. What are all the members of container control? Provides focus-management functionality for controls that can function as a container for other controls. Class: Provides focus-management functionality for controls that can function as a container for other controls. Namespace: System.Windows.Forms Assembly: System.Windows.Forms (in system.windows.forms.dll) 4. What is syntax for adding Menu and Menu Item? Adding a main menu : MainMenu mainmenu=new MainMenu(); This.Menu=mainmenu Adding menu items: MenuItem mifile=mainmenu.menuitems.add( &File ); mifile.menuitems.add(new MenuItem( &Open. ));

12 mifile.menuitems.add( _ ; //give as a separator mifile.menuitems.add(new MenuItem( Exit )); 5.What is pop up menu? How it is created? Pop-up ads or pop-ups are a form of online advertising on the World Wide Web intended to attract web traffic or capture addresses. Pop-ups are generally new web browser windows to display advertisements. The pop-up window containing an advertisement is usually generated by JavaScript, but can be generated by other means as well. 6.List out the properties of status bar. StatusBar control is not available in Toolbox of Visual Studio StatusStrip control replaces StatusBar in Visual Studio But for backward compatibility support, StatusBar class is available in Windows Forms. A StatusBar control is a combination of StatusBar panels where each panel can be used to display different information. For example, one panel can display current application status and other can display date and other information and so on. A typical StatusBar sits at the bottom of a form. 7.How to add images to toolbar buttons? Adding ToolTips to the ToolBar Buttons: ToolTipText property of Control class is used to Add ToolTips to ToolBar buttons. If tb1, tb2, tb2 are your ToolBarButton class objects, you can directly call ToolTipText to set tool tip for toolbar buttons. adding tooltips to the button tb2.tooltiptext = tb2.text tb1.tooltiptext = tb1.text tb3.tooltiptext = tb3.text 8.What is the difference between Radio button and Check box? Radio button: The radio button control appear in a group.

13 Only one option can be selected from a group. The System.WinForms.RadioButton class is used to create a radio button. Check box: The check box control is used for True/False option. More than one check box can be selected or a form at any instance. The System.WinForms.RadioButton class is used to create a check box. 9.What is the use of Track bar? TrackBar control provides scrolling with a little different interface than a scrollbar. Attaching TrackBar to a Control: Horizontal scroll bar control is attached to a control by its scroll event. On the scroll event hander, we usually read the current value of a TrackBar and based on this value, we apply on other controls. The simplest way to add an event handler to a TrackBar is by double click on it or go to Events window. The following code snippet is added for an event handler for the Scroll event. this.trackbar1.scroll += new System.EventHandler(this.trackBar1_Scroll); 10. What is Error Provider? The error provider control is most useful in displaying errors associated with data entry tasks on a Windows form. The error provider control is typically used to show errors related to data entry, however, the developer may also use it to display any desired icon and accompanying tool tip in response to any monitored event. For example, successful entries could be shown with a green checkmark as easily as failed entries could be shown with the standard red ball exclamation mark. 11.What is Masking Masking is a process of hiding the entire information.the data binding concept utilizes this kind Of process

14 Any of the field in the given data can be masked by this process. 12. What do you mean by group box? The GroupBox control displays a frame around a group of controls with or without a caption. GroupBoxes are used to subdivide a form by function, giving the user a logical visual cue of control grouping We can add controls to the GroupBox at design time and runtime. When move the GroupBox control, all of its contained controls move too. When create a new group box, it has a border by default, and its caption is set to the name of the control 13.How to Create a ToolTip for a Control? This example programmatically creates a ToolTip for a Windows Forms control. Example private void Form1_Load(object sender, System.EventArgs e) { System.Windows.Forms.ToolTip ToolTip1 = new System.Windows.Forms.ToolTip(); ToolTip1.SetToolTip(this.textBox1, "Hello"); } This example requires: A form named Form1 with a TextBox control named textbox1. Set Form1's Load event handler to Form1_Load. 14. What is combo box? What is the difference between list box and combo box? List Box : 1. Occupies more space but shows more than one value. 2. We can select multiple items. 3. we can use checkboxes with in the list box. Combo Box: 1. Occupies less space but shows only one value for visibility 2. Multiple select is not possible 3. can't use checkboxes within combo boxes 15.Difference between dataset & ADO s Record set

15 Dataset: It can hold more than one table from the same database. It can hold the relationship between the tables in dataset. ADO s record set: It can hold only one table from the same data source at any time. It cannot hold the relationship between the tables,because at any time only one table can exist in the recordset. 16.Define data adapter Bridges the data source & the disconnected dataset or data table classes. Data adapter wraps the connected classes to provide this functionality. 17. What is disconnected architecture?what is the advantage of this? In a disconnected architecture, data is retrieved from a database and cached on your local machine There are significant advantages to disconnecting your data architecture from your database. The biggest advantage is that you avoid many of the problems associated with connected data objects that do not scale very well. Database connections are resourceintensive, and it is difficult to have thousands (or hundreds of thousands) of simultaneous continuous connections. A disconnected architecture is resource-frugal. 18. List out the different types of applications that can be created on.net Console Applications Windows Applications Web Form App Window Service Web Service Class Library WPF app WCF Service App. 19.Write a window based application to display a message. using System.Windows.Forms; public class HandDrawnClass : Form private System.Windows.Forms.Label lbloutput;

16 private System.Windows.Forms.Button btncancel; this.lbloutput = new System.Windows.Forms.Label( ); this.btncancel = new System.Windows.Forms.Button( ); this.text = "Hello World"; lbloutput.location = new System.Drawing.Point (16, 24); lbloutput.text = "Hello World!"; lbloutput.size = new System.Drawing.Size (216, 24); btncancel.location = new System.Drawing.Point (150,200); btncancel.size = new System.Drawing.Size (112, 32); btncancel.text = "&Cancel"; protected void btncancel_click ( object sender, System.EventArgs e) { //... } btncancel.click += new System.EventHandler (this.btncancel_click); this.autoscalebasesize = new System.Drawing.Size (5, 13); this.clientsize = new System.Drawing.Size (300, 300); Finally, remember to add the widgets to the form: this.controls.add (this.btncancel); this.controls.add (this.lbloutput); protected void btncancel_click ( object sender, System.EventArgs e) { Application.Exit ( ); } public static void Main( ) { Application.Run(new HandDrawnClass( )); } PART-B 1.i.List out the categories of controls supported in window based application and explain the importance of each. ii. Explain the process of creating a window based calculator with your own UI.

17 2. i. Compare the architecture of ADO with ADO.NET ii. Write a database application to display the details of student table details in a datagrid control. 3.Write a program using ADO.NET to connect to the NorthWind database and read the names of the employees.the Employe table has 2 fields namely First Name and Last Name. 4. Implement the following in datasets: i. Adding a row ii. Adding a new data column iii. Deleting a row. iv. Updating a row. 5. Explain the processs of creating menus in a window based application.

18 WEB BASED APPLICATION DEVELOPMENT ON.NET PART-A 1. What are post-back events?give example. Postback events are those that cause the form to be posted back to the server immediately. These include click type events, such as the Button Click event. 2. Describe the features of web.config file. Web.config is the main settings and configuration file for an ASP.NET web application. The file is an XML document that defines configuration information regarding the web application. The web.config file contains information that control module loading, security configuration, session state configuration, and application language and compilation settings. Web.config files can also contain application specific items such as database connection strings. 3. What are the advantages of using server controls? Server controls or ASP controls have been designed to augment and replace the standard HTML controls.asp controls provide a more consistently named attributesfor eg.,using ASP controls <asp:radiobutton> <asp:checkbox> <asp:button> <asp:textbox rows="1"> <asp:textbox rows="5"> 4. List out the server side state management options supported by ASP.NET. Application state Application state is a global storage mechanism accessible from all pages in the Web application and is useful for storing information that needs to be maintained between server round-trips and between pages. Session state Like application state, using session state involves storing information in server memory. Using a database to store state In many cases, state information must be stored for long periods of time or must be preserved even if the server restarts. For this reason, using database technology to maintain state is a common practice. 5. Define SOAP Simple Object Access Protocol (SOAP) is a simple, universally accepted protocol for exposing, finding, and invoking web service functions.

19 SOAP has the advantages of being based on XML and of using standard Internet communications protocols. SOAP is a lightweight, message-based protocol built on XML, HTTP, and SMTP. 6. Delineate web services. Web services are encapsulated,loosely coupled contracted functions offered via standard protocols Web services are typically application programming interfaces (API) or Web APIs that are accessed via Hypertext Transfer Protocol (HTTP) and executed on a remote system hosting the requested services 7. Mention the protocols used for web services. XML- Extensible Markup language SOAP- Simple Object Access Protocol WSDL- Web Service Description Language UDDI Universal Description Directory Identification 8. Define WSDL The first of these is provided in.net by the Web Service Description Language (WSDL) protocol, jointly developed by Microsoft, IBM, and others. WSDL is an XML schema used to describe the available methods -- the interface -- of a web service. 9. Describe discovery Discovery enables applications to locate and interrogate web service descriptions, a preliminary step for accessing a web service. It is through the discovery process that web service clients learn that a service exists, what its capabilities are, and how to properly interact with it. A Discovery (.disco) file provides information to help browsers determine the URLs at any web site at which web services are available. When a server receives a request for a.disco file, it generates a list of some or all of the URLs at that site that provide web services. 10. What are the differences between HTML controls and Web controls? Web Server Controls i. Web Controls are feature rich controls. Calendar controls,datagrid,repeater, validation controls. HTML Server Controls HTML controls are small and light weight. ii. Viewstate support No viewstate support

20 iii. Inherit from System.Web.UI.WebControls Inherit from System.Web.UI.HTMLControls 11. What are ASP.NET 2.0 Page Life Cycle Events? 1.PreInit 2.Init 3.InitComplete 4.PreLoad 5.Load 6.Control events 7.LoadComplete 8.PreRender 9. SaveStateComplete 10. Render 11.Unload 12. How to Manage state in ASP.NET? We can manage the state in two ways. Clent based techniques are Viewstate, Query strings and Cookies. Server based techniques are Application and Session

21 13. How does ASP.NET respond to postback events? The <asp:button> objects automatically postback when clicked. You need not write any code to handle that event unless you want to do something more than postback to the server.if you take no other action, the page will simply be re-sent to the client. 14. How do you create a proxy? Microsoft have provided a tool called wsdl that generates the source code for the proxy based on the information in the WSDL file. To create the proxy, enter wsdl at the Windows command-line prompt, followed by the path to the WSDL contract. For example, you might enter: wsdl PART-B 1. i. Compare ASP with ASP.NET ii. Write a web baased application to implement a ticket status checking system. 2. Explain the web service architecture. What are the steps involoved in the creation and consumption of web services.explain with an example. 3. i. Describe in detail the lifecycle of webform. ii. Explain any one data bound control in a program. 4. Explain the creation of calculator web services.test this program using a client program. 5. i.list the different object models associated with ASP.NET and highlight the features of each object. ii. Summarize the validator controls and their applications in ASP.NET 6. Explain the steps involved in the creation of web services.

22 UNIT V THE CLR AND THE.NET FRAMEWORK PART-A 1. What are threads? How are they useful? Threads are represented as single runtime entity. This is used for concurrent execution of more than one event. There is also a type of thread called as multiple thread. 2. What is the use of versioning? Versioning solves the DLL tell problem, versioning cannot be done on private assemblies. Shared assemblies in.net are uniquely identified by their versions. 3. Define marshaling? If an object in processor wants to interact with an object in excel spreadsheet, it must communicate across of that class when something happens. 4. What are assemblies? Assembly is a reusable, versionable and the self describing building block of a CLR. These are the building blocks of.net framework applications. 5. What is the difference between SingleCall and Singleton? SingleCall is the server side web controls which controls in the communication. Singleton is a client side control program which controls the number of clients connected. 6. What are manifests? It is a part of metadata and each an every assembly has a manifests. It also gives identification information such as name, version, etc. List of types, resources for the assembly, list of modules to perform a task, map to connect public type with implementing code, list of assemblies. 7. What are the tasks in reflection? Viewing metadata Performing type discovery

23 Late binding Creating types of runtime 8. List out the parameters for finding the particular type members. Ther are 4 parameters: Member types Binding flags Member filter Objects 9. What are remoting? Remoting is the process in which when an object is marshall and, either by process and interacting a process or machine boundaries. 10. What are different numeric formats supported by C#? Formats specifiers from numerical formatting. Percent formatting. C,c for currency. E,e for scientific. 11. What are the attributes?highlight the features of any two attributes. An attribute is an object that represents data you want to associate with an element in your program. The element to which you attach an attribute is referred to as the target of that attribute. Custom attributes You are free to create your own custom attributes and use them at runtime as you see fit Intrinsic attributes Intrinsic attributes are supplied as part of the Common Language Runtime (CLR), and they are integrated into.net.

24 Many intrinsic attributes are used for interoperating with COM, You can organize the intrinsic attributes by how they are used. 12. What is DLL hell?how is it rectified in.net? DLL Hell refers to the set of problems caused when multiple applications attempt to share a common component like a dynamic-link library (DLL) or a Component Object Model (COM) class. Solutions: Applications must be self-describing. Version information must be recorded and enforced. Must remember "last known good." Support for side-by-side components. Application isolation. 13. What are PE files? On disk, assemblies are Portable Executable (PE) files. PE files are not new. The format of a.net PE file is exactly the same as a normal Windows PE file. PE files are implemented as DLLs or EXEs. Logically (as opposed to physically), assemblies consist of one or more modules. 14. Define metadata. Metadata is information stored in the assembly that describes the types and methods of the assembly and provides other useful information about the assembly. Assemblies are said to be self-describing because the metadata fully describes the contents of each module. 15. What is CLR? The CLR(Common Language Runtime) Responsibilities are Garbage Collection Code Access Security Code Verification IL( Intermediate language )-to-native translators and optimizer s 16. What is early and late binding? Everything is early bound in C# unless you go through the Reflection interface. Most script languages use late binding, and compiled languages use early binding.

25 Early bound just means the target method is found at compile time. Late bound means the target method is looked up at run time Binding usually has an effect on performance. Because late binding requires lookups at runtime, it is usually means method calls are slower than early bound method calls. 17. what are the serialization types supported in.net? Serialization is the process of saving the state of an object by converting it to a stream of bytes. The object can then be persisted to file, database, or even memory. The reverse process of serialization is known as deserialization. The serialization types are as follows 1.XMLserialization 2.Binaryserialization 3. Soap serialization 18. what is the difference between Manifest and Metadata? Manifest Metadata 1. Manifest describes assembly itself 1. Metadata describes contents in an assembly 2. Assembly name, Version number, Culture, 2. classes, interfaces, enums, structs, etc., and Strong name, list of all files, Type references their containing namespaces, the name of each and referenced assemblies type, its visibility/scope, its base class, the interfaces it implemented, its methods and their scope, and each method s parameters, type s properties, and so on 19.What are the two types of assemblies? Assemblies come in two flavors: private and shared. Private assemblies are intended to be used by only one application Shared assemblies are intended to be shared among many applications. 20. What are the three requirements to use a shared assembly? You need to be able to specify the exact assembly you want to load. Therefore, you need a globally unique name for the shared assembly. You need to ensure that the assembly has not been tampered with. That is, you need a digital signature for the assembly when it is built. You need to ensure that the assembly you are loading is the one authored by the actual creator of the assembly. You therefore need to record the identity of the originator.

26 PART-B 1. i. Explain the feature of CLR ii. What is reflection?explain its use with an example. 2. What is remoting?explain the steps involved in the process of creating a remoting application. 3. i. Describe about assemblies in detail. ii. What is reflection?explain with an example. 4. Write a remoting application which returns the maximum and minimum temperature of a given day. 5. i.what is metadata?how is it viewed in C# code?explain with an example. ii. Explain the process of executing a thread in C#. 6. How are distributed applications implemented in C#. on the.net framework?explain its architecture and implementation issues.

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