Interpolation in Kotlin

Interpolation in Kotlin means concatenating the values of variables or expressions into a string. Kotlin provides an easy way to interpolate strings by using string templates.

The syntax for string templates is to use a dollar sign ($) followed by a variable or expression in the curly braces ({ }). Here are some examples:

1. Interpolating a variable into a string:

val name = "John"
val message = "Hello, $name!"
println(message)

2. Interpolating an expression into a string:

val a = 10
val b = 20
val result = "The sum of $a and $b is ${a + b}."
println(result)

3. Interpolating a string of multiple expressions:

val firstName: String = "John"
val lastName: String = "Doe"
val age: Int = 35
val city: String = "New York"
val message = "${firstName.capitalize()} ${lastName.toUpperCase()} is $age years old and lives in $city."

println(message)

Note that you can use any valid expression inside the curly braces, including method or property calls, arithmetic or logical operations, and even nested expressions. Interpolation in Kotlin is a powerful and concise way to construct strings with dynamic content.