#9.5 Kotlin Tutorial for Android: WITH and APPLY. Lambdas and High Level Func PART-5 Video Lecture | Kotlin Tutorial for Beginners: Learn Kotlin in easy language - Back-End Programming

hi this is ring Siddharth once again in
the previous videos we have covered
almost all the topics related to lambdas
and high-level functions so please check
those out now in this video we are going
to check out the concept of with and
apply that is present in the coeur
d'alene standard library so here inside
the IntelliJ IDE I have a class of
person with the property of name and age
right having some default value now down
the side I am having a method of start
run so inside the main method I have
simply created the object of person
given it some values shrink an age 23
and simply printing out the values now
this is the normal way of initializing
the objects right but if you notice here
we are simply repeating the person dot
name person dot age again and again but
this is Scotland not Java we can make
our code more cleaner so here again we
can simply use lambdas to make our code
look more cleaner and also reduce the
redundancy of the code so here I will
simply use with keyword with and as a
parameter simply pass person object now
then I will simply define the lambda
right that is curly bracket open and
close now inside the lambda I will
simply cut these two lines of code and
paste it inside the width statement but
here we do not have to repeat the person
object again and again we can simply use
name equal to strength and a is equal to
23 now if I run the code right now I
will simply get name as Sri and age as
23 so this width keyword is actually the
part of Cortlandt standard library not
the Kotlin language right now apart from
width we also have the apply keyword
which is again the part of the Cortlandt
standard library now to use the apply
keyword we have to use person dot apply
and inside this again we have to define
our lambda right so here I will simply
copy the code from here
paste it here if you want you can give
some different values and then if you
run the code then this code will act
similar to this code but in case of
apply it actually returns a receiver now
the receiver in our case is person and
apart from this this apply keyword has
the right to call these methods such as
start Turin present inside the class of
person so here if I want you can also
use dot keyword then start run so after
initializing the name a string and age
as 23 we can simply call this method of
start run that will simply execute this
method and simply print now I am ready
to run because all the values has
already got initialized that is named as
shrink and age 23 right but in case of
with keyword you cannot call the start
run method it will show some error
unresolved reference so this is the
difference between the width and apply
keyword and again remember these two are
again very important in terms of Android
application development now at last I
would like to tell you that till now
whatever codes that we saw in case of
lambdas and high-level functions are
just the basics and fundamentals the
practical usage of lambdas and
high-level functions we will check out
in our upcoming modules then we will
talk about the collections in detail so
as of now this much information is
enough for this module thanks for
watching and have a good day
this is Cheng Cesare signing off thank
you