#4.5 Kotlin RANGES and DOUBLE DOT Operators Video Lecture - Kotlin Tutorial

hi registering Siddarth once again
welcome to the next video of the series
of cortland programming now in this
video we will talk about what are ranges
in case of Kotlin now in case of Kotlin
we have some concept related to range of
values or range of characters as for
example here I have simply defined value
r1 equal to 1 then followed by dot
operator dot operator v now this is
actually known as the double dot
operator
so in Cortland if you define 1 double
dot v then this are one variable will
simply contain the range of values such
as 1 2 3 4 and 5 and these are the
sequence in which the values has been
stored inside the value r1 right now
suppose I want the value in the
descending order so for that we have
this example so here you can notice
value R 2 equal to 5 down to 1 so in
this case we have the range of values in
the descending order such as 5 4 3 2 1
like this now here you can also have 50
down to let's say 10 or 1 then in that
case we will have 50 49 47 46 and so on
till we reach 1 and now suppose I want
the values from 5 to 1 but I do not want
this for value and to value so for that
we have another example such as 5 down
to 1 in the step of 2 so when we start
counting from 5 to 1 we will count like
this 5 then then 3 then when so we are
actually moving towards 1 in the step of
2 that is we are actually skipping every
alternate value from 5 to 1 like this
now instead of 2 you can also have 3 4
like this fine
so in that case the steps will change
now in the first case suppose I want the
values such as 1 3 & 5 that is every
alternate value in the ascending order
will be skipped similar to the case that
we have
in here so in that case you just need to
write ste P space let's say two so in
that case this two and this four will
not exist inside this value right and
now apart from integer values we can
also have the range defined for the
characters such as well are four equal
to let's say from the alphabet a dot dot
two alphabet Z so in this case we have
the are four value defined as a b c d e
f till z right so the whole alphabets
has been defined in just one variable of
r4 and now apart from this string
characters you can also have the
character alphabets such as within the
single quotes right now these are all
about the ranges now later on suppose
you want to test this are for suppose
you want to check if this c character is
actually present inside this r4 or not
so for that simply define where is
present such as a variable name equal to
let's say a with the help of in operator
we can simply check if a is actually
present inside the r4 or not or if we
want to check if the character c is
actually present inside the r4 range or
not so if present will simply get the
value of either true or false but in
this case it will get the value of true
because c is actually present inside
this range and in similar way you can
use the in keyword for these range as
well right to test if the number is
present inside these ranges or not and
now apart from this you can also have
the ranges such as where or well let's
say count down equal to if you want to
count down from 10 dot down to let's say
when so in this case this countdown is
actually the range of values where we
are counting down from 10 to 1 so it
will simply contain all the integer
values from 10 to 1 right like this 10 9
8
seven six five four three two one and
now to have the value in the ascending
order
you can simply replace it by let's say
range to write so let us check that
example as well
so here this range to method simply
increments the value from one two three
four till ten right like we have done
here range two so down to and range two
are actually opposite to each other and
now this one is actually comparable to
let's say this one right and now
similarly this our two range is actually
comparable to let's say this count down
find another question arises why we are
actually learning the ranges in court
lengths just because these range of
values are actually helpful while
running the loops in Kotlin so we are
going to use this ranges concept in our
upcoming modules then we are going to
learn about loops in Cortland so that's
all for this video
catch you in the next video thank you