**More Information**
* [The code being referenced](https://github.com/Kotlin/kotlin-koans/tree/master/src/i_introduction/_6_Data_Classes).
* This is the 7th post in a multipart series.
If you want to read more, see our [series index](/learning-kotlin-introduction)
WOW! [Data Classes](https://kotlinlang.org/docs/reference/data-classes.html) are awesome! I really like a lot of how [classes are handled in Kotlin](https://kotlinlang.org/docs/reference/classes.html), but Data Classes are the pinnacle of that work. The effort for this Koan is to convert this Java class to Kotlin:
package i_introduction._6_Data_Classes;
import util.JavaCode;
public class JavaCode6 extends JavaCode {
public static class Person {
private final String name;
private final int age;
public Person(String name, int age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
}
}
and what does that look like in Kotlin?
data class Person(val name: String, val age: Int)
Yup, a single line. The data annotation adds a number of important functions (like `ToString` and `copy`). We then declare the class with a constructor which takes two parameters which both become properties.
Another important aspect I learnt with this one is that Kotlin has both a `val` and `var` keyword for variables. We have seen `var` already and `val` is for read-only variables.
