#4.4 Kotlin String Templates: Interpolation Video Lecture | Kotlin Tutorial for Beginners: Learn Kotlin in easy language - Back-End Programming

hi registering Siddarth once again
welcome to the next video of Cortland
programming series now in this video we
will learn about what our string
templates or in other words what is
string interpolation now in case of
cortland we have a special type of
concept of string interpolation so for
that let us take some example so let us
define some value let's say value space
name equal to Sam and then let us define
another value such as Val space str
equal to hallow space and then append
name at the end now here let us print it
by using STR so in the output we will
get hello Sam as expected so here is the
output hello Sam now in Cortland we have
a special concept of string
interpolation that is we no longer need
to use the plus key word or the string
concatenation now what is string
interpolation so for this we can simply
remove name from here and within the
hello we can simply use a dollar symbol
followed by name right so the Java
compiler what it will do it will simply
evaluate name and then print hello in
front of Sam so let us now run the code
so here in the output we get hello Sam
as expected as we got in the previous
run now let us take some more example we
can also apply the interpolation for
this STR variable right so here what I
will do I will simply print a statement
the statement is plus STR now instead of
using the plus STR here we can also use
a dollar symbol followed by STR right
and simply remove the plus STR from here
so in the output we will get the
statement is hello Sam
so here is the output the statement is
hello Sam and now proceeding forward let
us take one more example such as the
statement is hello Sam and then full
stop followed by the number of
characters
in statement is let's say name is STR
dot length that is this will simply
return the length of the string right so
here I will use a dollar symbol now
whenever we use the dollar symbol it is
only applicable for the variable right
after this so this dollar symbol is only
applicable for this STR so let's see
what happens in the output so in the
output we get the number of characters
in the statement is hello Sam dot length
but our objective was to print the
number of characters present inside this
statement that is hello Sam so for that
we need to apply the interpolation on
this length variable right and now this
length is actually dependent on this STR
string so we cannot apply the dollar
symbol right here like this this will
simply result in error so for this we
need to simply use the curly bracket
open and then at the end close so the
court line compiler what it will do it
will simply evaluate this statement here
and then apply the interpolation on hole
right that is length so let us now
execute our code so here we go the
number of characters in the statement is
nine so this statement is actually
actually contains nine characters now
proceeding forward let us take some more
example let's say Val a equal to 10 and
then Val be equal to 5 and now let us
print something the sum of a and B is
something so I want to print the number
variable a and also the number variable
B and also I want to print the sum of
these two numbers so with the help of
interpolation what we can do we can
simply apply the dollar symbol here and
also a dollar symbol here and then we
can simply apply dollar symbol here and
simply type a plus B now as per the
stuff that we saw in the previous
example this dollar symbol is only
applicable for a but I want to execute
the
interpolation as a whole here so for
this we need to again use the curly
bracket open and then curly bracket
closed and now let us run our code so in
the output we get the sum of ten and
five is 15 now this is the beauty of
Cortland in just one statement you can
print everything so that is why we say
the Cortland is more powerful than Java
and it is more expressive and concise
less number of code but more output
apart from this if suppose we define the
class let's say rectangle
now please don't worry we will discuss
about the class in our upcoming modules
as of now I am simply giving you an
example let's say length :
and also define the width : in equal to
zero and now here inside the print
statement I want to print the length of
the rectangle is this much and breadth
is this much and the area of the
rectangle is length into breadth so I
want to print the value in just one
print statement so for this what I will
do I will simply create a where
rectangle equal to let's create a new
object now these are some basic steps
that we already saw in the previous
module right now here I will simply
initialize red dot length equal to 5 and
Rec dot length equal to 3 and now here I
will simply use the interpolation so in
place of length I will simply use red
dot length right and simply apply the
interpolation on whole so we need to use
the curly bracket here and then close it
and don't forget to put a dollar sign
here right
similarly dollar symbol dollar symbol
here curly bracket open and close and
now correct dot breadth and then the
area of the rectangle is let's say
dollar curly bracket open and close
correct dot length asterisk correct dot
breadth fine
and now let us turn our code so in the
output we get the length of the
rectangle is 5 bread is 3 and the area
is 15 so how beautifully we have simply
applied the interpolation and printed
out the output in just one statement
right so this was all about the string
template in Cortland