Sqldataadapter Update Dataset Multiple Tables Php MysqlSqldataadapter Update Dataset Multiple Tables Php ArrayTop Frequently Asked Questions in.Net Interview. 1.What is the difference between an abstract class and interfaces Probably Difference Between abstract Class and Interface is the most frequent question being asked in the.Net world. In this tutorial, I will explain the differences theoretically followed by code snippets.Theoretically there are basically 5 differences between Abstract Classes and Interfaces as listed below.Issuu is a digital publishing platform that makes it simple to publish magazines, catalogs, newspapers, books, and more online.Easily share your publications and get.In this article you will learn about the most asked ADO.NET Interview questions and answers.If you need to check if an email address really exists, this.Net component is for you.How it works This free asp.Update I dont know VB but here is what I think it would look like cmd New SqlCommandSelect from table1, con ada New SqlDataAdaptercmd ds New DataSet.A class can implement any number of interfaces but a subclass can at most use only one abstract class.An abstract class can have non abstract methods concrete methods whereas all methods of interfaces must be abstract.An abstract class can declare or use any variables whereas an interface is not allowed to do so.The following code compiles properly since no field declaration is in the interface.Test. Interfaceint x 4 Filed Declaration in Interfacevoid get.Method string get.Name abstract class Test.Abstract. Classint i 4 int k 3 public abstract void get.Class. Name It will generate a compile time error as Error.Interfaces cannot contain fields.So we need to omit the Field Declaration to compile the code properly.Test. Interfacevoid get.Sqldataadapter Update Dataset Multiple Tables Php Code' title='Sqldataadapter Update Dataset Multiple Tables Php Code' />Method string get.Name abstract class Test.Abstract. Classint i 4 int k 3 public abstract void get.Class. Name An abstract class can have a constructor declaration whereas an interface cannot.So the following code will not compile interface Test.Interface Constructor Declarationpublic Test.Interfacevoid get.Method string get.Name abstract class Test.Abstract. Classpublic Test.Abstract. Classint i 4 int k 3 public abstract void get.Class. Name The code above will generate the compile time error Error 1 Interfaces cannot contain constructors So we need to omit the constructor declaration from the interface to compile our code.The following code compiles perfectly interface Test.Interfacevoid get.Method string get.Name abstract class Test.Abstract. Classpublic Test.Abstract. Classint i 4 int k 3 public abstract void get.Class. Name An abstract class is allowed to have all access modifiers for all of its member declarations whereas in an interface we cannot declare any access modifier including public since all the members of an interface are implicitly public.Note here I am talking about the access specifiers of the member of interfaces and not about the interface.The following code will explain it better.It is perfectly legal to provide an access specifier as Public remember only public is allowed.Test. Interfacevoid get.Method string get.Name The code above compiles perfectly.It is not allowed to provide any access specifier to the members of the interface.Test. Interfacepublic void get.Method public string get.Name The code above will generate the compile time error Error 1 The modifier public is not valid for this item.But the best way of declaring an interface will be to avoid access specifiers on interfaces as well as members of interfaces.Testvoid get. Method string get.Name 2. What is the difference between overriding and overloading Overloading.In this approach we can define multiple methods with the same name changing their signature.In other words different parameters.This can be performed within a class as well as within a child class.Doesnt require any permission from the parent for overloading its method in the child.Overriding. It is an approach of defining multiple methods with the same name and the same signature.This can be performed only under child classes.Requires an explicit permission from the parent to override its methods in the child.String Builder and String class String A string is a sequential collection of Unicode characters that represent text.String is a class that belongs to the namespace System.String. String concatenation can be done using the opearator or the String.Concat method. The String.Concat method concatenates one or more instances of a String.Sample code string string.Today is Date. Time.Now. To. String D .Console. Write. Line string.Hi This is Jitendra string.Sampathi. Rao. Console.Write. Linestring.String. Builder. String.Builder is a class that belongs to the namespace System.Text. This class cannot be inherited.In String. Builder we use the Append method.Sample code. String.Builder number new String.Builder 1. 00. 00 for int i 0 ilt 1.Number. Append i.To. String So where do we use these classes The answer is for simple String manipulations we can use the String class.But when there are more string manipulations it is better to use the String.Builder class. Why is the String.Builder class better for more string manipulations instead of the String class The String object is immutable.Every time you use one of the methods in the System.String class, you create a new string object in memory, that requires a new allocation of space for that new object.In situations where you need to perform repeated modifications to a string, the overhead associated with creating a new String object can be costly.The performance of the application might be degraded.So we use String.Builder in such cases.A String. Builder object is mutable.The System. Text.String. Builder class can be used when you want to modify a string without creating a new object.For example, using the String.Builder class can boost performance when concatenating many strings together in a loop.Differences between String and String.Builder. It belongs to String namespace.It belongs to String.Text namespace. String object is immutable.String. Builder object is mutable.Assigning String.Builder sbuild new String.Buildersomething important Assigning String s something important We can use the operator or Concat method to concatenate the strings.We use the Append method.When string concatenation is done, additional memory will be allocated.Here additional memory will only be allocated when the string buffer capacity is exceeded.What is the difference between array and array list Mirosoft.Net has many namespaces for many purposes.Among them the System.Collections is a very important namespace in the programmers perceptive.While coding, we look for classes that can reduce manual operation.For instance if you want to sort the values in an array then you need to do the manual operations.Here obviously we look for the classes that can automate the sorting by just calling a method.In other words we can call this namespace as a utility namespace.Let us see the classes in this namespace.Collection Classes.The System. Collections namespace has many classes for the individual purpose.We will discuss the frequently used classes in this article.Array. List. Bit.Array. Stack. Queue.Comparer. Hash. Table.Sorted. List. Array.List. The Array. List is one of the important classes in the System.Collection namespace.We can say it is the next generation of the Array in C.Array. List is a dynamic array it will increase the size of the storage location as required.It stores the value as an object.The allocation of the Array.List can be done through the Trim.To. Size property.Methods. 1Add. It will add the element as object in the Array.List. 2Add. Range.It will add the collections of elements in the object as individual objects in the Array.List. 3Clear. It will clear the all objects in the Array.List. 4Binary. Search.It will return the position of the search object as integer value.Insert. It will insert the element in the specified location of the index in the Array.List. 6. Insert. Range.It will insert the elements in the object as individual objects in the specified location.Remove. It will remove the given object in the first occurrence in the Array.List. 8. Remove. At.It will remove the object as specified in the argument.Remove. Range. It will remove the set of objects in the Array.List from the range specified.Sort. It will sort the elements in ascending order.Reverse. It will arrange the elements in the reverse order in the Array.List. 1. 2Get. Enumerator.It will return the collection of objects in the Array.List as an enumerator.Contains. It checks whether the objects exist.Properties in the Array.List. S. No. Property Name.Description. 1Capcity.This property sets or gets the size of the Array. Free Download Adobe Flash For Firefox . List. As you know it will increase the size of the storage as much as required.The default size will be 1.Free Asp. Net Email ValidatorVerifier.If you need to check if an email address really exists, this.Net component is for you.How it works. This free asp.Check Email Syntax An accurate syntax check.Check if a domain name has MX records.Read Mx records get the mx records for a domain name or an email adress.Check SMTP Server verify that the SMTP server is working and accept connections.Check Mailbox validity connect to an email server directly via SMTP to check if mailbox is validThis component requires the Microsoft.NET framework and can be used in your website webforms or application winforms.Add a reference to the dll or copy the file E mailValidator.It does not have a GUI front end, it is a component that can only be accessed programmatically, just create an instance Codicode.Email. Validator EV new Codicode.Email. Validator please note that some mail servers always return a positive response even if the mailbox doesnt exist.C code sample. The following code will verify the validity of the email address, if no error was returned, then the email address is valid and can accept mails, if not and error message will be returned account dosnt exist, no mx records, smtp timeout.We create an instance of our e.Mail Validator Object.Codicode. Email. Validator Ev new Codicode.Email. Validator.Set the Sender email for smtp identification.Ev. MailFrom adminmonoprog.Check if the email address is valid and really exists.Msg Ev. CheckMail.BoxErrortb. Email.Text. if error. Msg.Mail AddressSmtp is valid and running.Status. Text Mail OK.An error occured while validating the email.Status. Text error.Msg. Close and Dispose.The following code will retrive the MX records list from an emails domain name.We create our e. Mail Validator Object.Codicode. Emailvalidator Ev new Codicode.Emailvalidator. Get the domains MX records.MxRecords Ev. Find.MXRecordstb. Email.
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