Interface
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Ahamed Azeem wrote:
Tell me an real time use of an interface.
The question is rather unclear; it sounds as if you're requesting for an example of an interface in a real-time environment, but I'm going to guess that you want a practical example where we use interfaces. How about
IDbConnectionandIDbCommand?Ahamed Azeem wrote:
Apart from importing namespace is there any use for "Using" keyword in C#.net.
Yup, both as a naming-alias for existing namespaces, as well as defining scope for a class that implements
IDisposable.I are Troll :suss:
Thank your for your reply. Why do we want to go for interfaces rather than normal method definition. Your second answer is not clear to me. Could you pls explain more Regards Azeem
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Thank your for your reply. Why do we want to go for interfaces rather than normal method definition. Your second answer is not clear to me. Could you pls explain more Regards Azeem
Ahamed Azeem wrote:
Why do we want to go for interfaces rather than normal method definition.
Mostly to prevent thight coupling, but there may be other reasons. An interface just says how the "normal method definition" should look, it doesn't contain any implementation; that means that if a class implements an interface that you can be sure that this class has all the properties and methods that are defined within the interface. A variable of the type
IDbConnectioncan hold aSqlConnectionor aOracleClientConnection. You could only talk to Sql Express if you used aSqlConnectionvariable. There's a better explanation of that idea over here[^].Ahamed Azeem wrote:
Your second answer is not clear to me. Could you pls explain more
The first alternative usage is a namespace alias[^]. That would allow you to "rename" the namespace. This is common in Office-development to shorten the namespaces. As an example;
static class SomeClass
{
static void someMethod ()
{
System.Diagnostics.Debug.WriteLine("bla");
}
}With a namespace-alias, it would look like this;
using Diag = System.Diagnostics;
static class SomeClass
{
static void someMethod ()
{
Diag.Debug.WriteLine("bla");
}
}The second alternative[^] use is what the "interviewer" wanted to hear, and looks like this;
using (Font font1 = new Font("Arial", 10.0f))
{
byte charset = font1.GdiCharSet;
}This ensures that
IDisposableis called cleaning up theFont.Happy Reading :)
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Hello, In an interview asked to me that, Tell me an real time use of an interface. Apart from importing namespace is there any use for "Using" keyword in C#.net. Could anybody can answer these question. I would be very thankful to you Regards Azeem
Ahamed Azeem wrote:
real time use of an interface
This is what I can think right away: I am owner of an application. There are two distant and independent teams which are working on it. One on UI and other on rest of the layers. Now, as an owner, what I can do is provide both the teams with a interfaces so that they can work independently and be sure of what is the middle and DB layer is going to offer and what UI is supposed to consume. There are plenty more uses of interfaces, one being dependency injection, which you might find through google. :)
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Hello, In an interview asked to me that, Tell me an real time use of an interface. Apart from importing namespace is there any use for "Using" keyword in C#.net. Could anybody can answer these question. I would be very thankful to you Regards Azeem
Hi, IMO you should buy and study a book on C# or change your career plans; those were very basic questions after all. :|
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
Getting an article published on CodeProject should be easier and faster.
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Hi, IMO you should buy and study a book on C# or change your career plans; those were very basic questions after all. :|
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
Getting an article published on CodeProject should be easier and faster.
-
Hello, In an interview asked to me that, Tell me an real time use of an interface. Apart from importing namespace is there any use for "Using" keyword in C#.net. Could anybody can answer these question. I would be very thankful to you Regards Azeem
Ahamed Azeem wrote:
for "Using"
Real time use of an interface - Late binding. "Using" is often used to define a scope inside which an object will be garbage collected. As suggested, you need to pick up a good C# book and read.
Me, I'm dishonest. And a dishonest man you can always trust to be dishonest.
Honestly. It's the honest ones you want to watch out for... -
Hi, IMO you should buy and study a book on C# or change your career plans; those were very basic questions after all. :|
Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]
Getting an article published on CodeProject should be easier and faster.
Dear Gentleman, Is there any rule that basic question would not be answered.. I am very good fan of this forum. Regards Azeem
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Ahamed Azeem wrote:
Why do we want to go for interfaces rather than normal method definition.
Mostly to prevent thight coupling, but there may be other reasons. An interface just says how the "normal method definition" should look, it doesn't contain any implementation; that means that if a class implements an interface that you can be sure that this class has all the properties and methods that are defined within the interface. A variable of the type
IDbConnectioncan hold aSqlConnectionor aOracleClientConnection. You could only talk to Sql Express if you used aSqlConnectionvariable. There's a better explanation of that idea over here[^].Ahamed Azeem wrote:
Your second answer is not clear to me. Could you pls explain more
The first alternative usage is a namespace alias[^]. That would allow you to "rename" the namespace. This is common in Office-development to shorten the namespaces. As an example;
static class SomeClass
{
static void someMethod ()
{
System.Diagnostics.Debug.WriteLine("bla");
}
}With a namespace-alias, it would look like this;
using Diag = System.Diagnostics;
static class SomeClass
{
static void someMethod ()
{
Diag.Debug.WriteLine("bla");
}
}The second alternative[^] use is what the "interviewer" wanted to hear, and looks like this;
using (Font font1 = new Font("Arial", 10.0f))
{
byte charset = font1.GdiCharSet;
}This ensures that
IDisposableis called cleaning up theFont.Happy Reading :)
Thanks a lot.. now i got it Regards Azeem
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Dear Gentleman, Is there any rule that basic question would not be answered.. I am very good fan of this forum. Regards Azeem
That's not the problem. The problem is that you were interviewing for a C# job without knowing the most basic concepts of C# and OOP programming.
A guide to posting questions on CodeProject[^]
Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
2006, 2007, 2008
But no longer in 2009... -
That's not the problem. The problem is that you were interviewing for a C# job without knowing the most basic concepts of C# and OOP programming.
A guide to posting questions on CodeProject[^]
Dave Kreskowiak Microsoft MVP Visual Developer - Visual Basic
2006, 2007, 2008
But no longer in 2009...Thank you