Part 9 - C# Tutorial - Comments in C#.avi Video Lecture - C sharp Enhance

hello welcome to prism technologies i'm
venket this is part 9 comments in
c-sharp in this session we will learn
single line comments multi-line comments
and we'll also have an introduction to
XML documentation comments there's a
great deal to learn about XML
documentation comments which we'll be
talking about in a later session so what
are comments in general comments are
basically used to document what the
program does for example if there is a
confusing piece of school and if you
want other developers to know what that
particular piece of code is doing you
can basically comment that lines of code
and when we talk about commenting in
c-sharp there are actually three ways of
doing it you can comment single line
using forward slash four slash or you
can comment multiple lines using forward
slash Astrix and Astrix forward slash
let's look at a demo say I have some
piece of code like this console dot
readline hello and let's make a copy of
this line just to make sure we have some
pieces go to comment and comment now I
can comment the single line so to
comment a single line we use fours left
four slash obviously when we run this
program this line will be ignored by the
compiler okay so it doesn't compile this
piece of fly okay so this is a single
line comment but if you want to comment
you know even this line you can also for
slash four slash similarly this line
okay but if you want all these three
lines to be commented instead of using
in a four slash forward slash for every
line what you can actually do is use
multi-line comments for slash Astrix
that's the beginning of the comment and
to end it as trick and another four
slash so this entire block is now
treated as a comment okay depending on
your situation if you want to comment
multiple lines you can make use of
multi-line comments if you want to
comment justice in the line make use of
single line comments
now do not comment every line in your
program you know that's not why comments
are there if you feel a particular piece
of code is complicated only then try to
comment that otherwise there's no point
and actually commenting each and every
line of your program for example if I
have a piece of code like this that's a
string city equals something London and
we have a check here if city equals
maybe London and we want to maybe say
console dot write line something okay
now somebody you know with a comment
here F city is London there's no need to
do this because this code is self
explanatory so we don't have to come
this line okay so that's what use
comments only the piece of code that
you're trying to you know explain is
complicated if it's straightforward like
this we don't have to comment that it's
just waste of space and time okay and
basically there are two ways to comment
one is you can use the designer for
example if I want to comment this line I
can use the designer here comment out
these selected lines and if I would one
comment you can do the undo uncommon but
okay that's using the designer another
ways is to actually use the keyboard
shortcut which is faster and quicker so
and the keyboard combination for that if
you see the slide it's ctrl K control C
control K is common so control K and
ctrl C to comment uncomment control K
control you so control K is comma C for
comment you for uncle that's how I
remember that just gets if you're
wondering a way to remember them so
control K control C comment okay and
observe the status bar here at the
bottom left
corner when I press ctrl K it says ctrl
K was pressed waiting for the second key
you know so control you now it will
uncomment that okay anyhow so there are
two ways basically to comment a nun
comment using the designer by using the
keyboard shortcut another tool you don't
try to comment every line of code use
comments only four blocks lines of code
that are difficult to understand and we
look at XML documentation comments I'll
just give you an introduction of what
XML documentation comments are but
there's a great deal to learn about them
which we will be doing in a later
session okay now let's say I want to
make use of this console class in a
moment I type in the console class when
I hover my mouse the deletions tells me
the summary of this class basically
telling me what this class is capable of
doing so this class if you look at that
intellisense there it represents the
standard input output and error streams
to comes well application so where is
this information is coming from okay if
I right-click that and say and say go to
definition okay this is actually coming
from the Microsoft assembly ok this
class is compiled and still is presented
in Microsoft assembly so Microsoft has
written that class similarly we can also
write classes for example let's write a
sample class and we will be talking
about classes in a great detail in a
later session so let's call this public
class maybe sample class just to give it
a meaningful name okay
now let's not worry about the inner
details of this particular class what it
does so let me create an instance of
this class so when I say sample class
and look at this when I hover my mouse
over there it doesn't show me any
summary of what this class is capable of
doing because we don't have those XML
documentation comments and the way we
can tell what this class is capable of
doing is by using the XML documentation
comments let's look at if you go back to
our slides
XML documentation comments they use
three four slashes okay so
four slash four slash four slash look at
this it automatically gives us that
somebody tagged this is a sample class
and a sample documentation just to
illustrate so now if I go ahead and
hover my mouse over this class we get
that that documentation that summer even
though somebody tags is actually shown
in the intellisense so this is just the
tip of the iceberg of what you can do
with xml documentation comments anyway
as a summary in c-sharp there are three
types of comments single line comments
multi-line comments and xml
documentation comments single line
comments if you want to comment s in the
line multi-line comments to comment a
block of flack of code and xml
documentation comments obviously for
documentation purposes thank you for
watching have a great day