When the sole responsibility of the class is to hold some data, the data should be in presentable form. A data class provides the toString() function to display well-formatted class properties. Let's have a look at an example:

1. Create a Person data class:

data class Person(var name : String, var age: Int, var height: Double)

2.  Display all properties using string interpolation or concatenation:

println("Name ${person.name}, Age ${person.age} Height ${person.height}")

3. Call the toString() function using the person object as a reference, person.toString().
4. The toString() function converts the object into a string representation.

Check the following example:

ClassName (property=value)
fun main(args: Array<String>) {
    val person = Person("Abid", 40, 6.0)
    println("Name ${person.name}, Age ${person.age} Height ${person.height}")
    println(person.toString())
 } 

Take a look at the output; the toString() function combines each property along with its value in string-representation format:

The benefit of the toString() function is that Kotlin will automatically update the toString function if we add a new property or remove the existing one:

data class Person(var name :String, var age :Int, var country :String)
println(person.toString())

The toString() function can either be called explicitly, by using the println(person.toString()) object, or it can be called automatically, by passing the object to the print function, println(person).