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So in this video, we're going to talk about Question 14, one of the most common questions during C-sharp

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interviews.

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What is the difference between Troll and Troll X when catching an exception?

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We don't always wants to handle it and read the program execution continue.

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Sometimes we want the exception to move on and perhaps be caught in the next cut growth.

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But we want to look something or do another action related to this exception occurrence.

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Such a field is called exception redrawing.

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We can do it by either using Troll Auto X. The difference is that through preserves the stack trace,

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so the Stack Trace will point to the method that caused the exception in the first place.

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While Strokes does not preserve the stack trace, it means we will lose the information about the method

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that caused the exception in the first place.

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It will seem like the exception was drawn from the place of its cutting and redrawing.

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We will see this in the court in a second, but first, let's be sure we understand what the stack traces.

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The stack trace is a trace of all methods that have been called that led to a particular moment in the

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code.

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Let's consider the following code.

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As you can see, method calls method we would call Smith at sea in the Method C will log the current

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state of this Darktrace.

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Let's see what will be printed to the council if we call metadata from the main method of the program.

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At the top of the stack trace, we have the method that has been called most recently.

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And at the bottom, the one that has been called first, the Stack Trace stores the information about

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automated calls that led to the current moment in the program execution.

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As you can see, the glitter of the environment stack trace property is at the very top because we read

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the Stack Trace, which is this method.

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Exactly.

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So it's the latest to be called.

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Please note that also the numbers of the lines of code where those methods have been called are stored

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in this Darktrace Stack Trace has many uses.

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But for us as developers, the most important value it brings is that it helps us track were some exceptions

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happened.

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Imagine that you have a huge up and when it throws an exception, oh, it says object is no.

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Well, that wouldn't be very helpful.

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We want to know the exact method that caused the problem and even more the exact line.

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This will help us to take a look at the right place.

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Put a breakpoint there and overall solve the problem easier and faster.

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All right.

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We said that True preserves the stack trace, well, Joe X doesn't want it is sometimes called resetting

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this Darktrace.

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Let's see the code that will show us the difference.

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Here is the first method.

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As you can see, it's designed to throw an exception because it will try to access the first number

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in an empty collection.

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And here is the second method.

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Almost the same, but doing through X instead of throw.

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As you can see, Visual Studio underlines throw eggs, and it has good reasons to do so.

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We'll go back to it in a while.

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First, let's see those methods in use for both of them.

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I called them in the try book in the catalog.

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I'm simply writing the stack trace stored in the exception.

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And now let's see the output of the program.

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For all the stack, trace and isolate links to her power, the previous entry serves about the first

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method, which already gives us some information about the nature of the problem for Trail X, the Stack

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Trace and admitted Troll X Line 52.

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What is this one?

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Exactly?

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This means that all information that has been stored in the stack trace before reaching the troll comment

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is lost.

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This is not good for us as we lose valuable data about the origins of the exception.

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This is why here we see Visual Studio suggesting to us that using Troll X is not a very good idea.

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We should stick to using Troll, not through works.

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One may wonder why is there a possibility to do it in C-sharp at all?

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If we should not ever use it?

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Well, remember that this X is just an object.

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Although exception grass.

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We throw objects belonging to this class all the time, and it's perfectly fine only that we troll brand

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new exceptions, not the ones that have already been thrown.

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If C-sharp allows me to do this with the argument exception object, it must allow me to do this with

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this object, which is also an exception.

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The compiler can truly prevent us from doing so, even if it's not such a good idea.

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Let's summarize the difference between Troll and Troll X is that troll preserves the stack trace while

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or X does not do that with the Troll X will lose the information about the origins of the exception,

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and instead, it will seem like the exception was strong from the place of its cutting and trolling.

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Questions related to this topic that you may feel during the interview could be.

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What is the Stack Trace?

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The Stack Trace is a trace of all methods that have been called, and that led to the current moment

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of execution at the top of the Stack Trace.

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We have the method that has been called most recently and at the bottom.

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The one that has been called first stack trace allows us to locate the exact line in the code that was

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the source of an exception should be a strong or true X and Y.

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We should use Troll as it preserved the stack trace and helps us find the original source of the problem.

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All right, that's it about the topic of exceptions.

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Thanks for following along and see you in the next video.