Using constants efficiently

Since everything in Java is an object (unless it's a primitive type), we're used to putting all the constants inside our objects as static members.

And since Kotlin has companion objects, we usually try putting them there:

class Spock {
    companion object {
        val SENSE_OF_HUMOR = "None"
    }
}

This will work, but you should remember that companion object is an object, after all.

So, this will be translated into the following code, more or less:

public class Spock {
    private static final String SENSE_OF_HUMOR = "None";
 
    public String getSENSE_OF_HUMOR() {
        return Spock.SENSE_OF_HUMOR;
    }
    ...
}

In this example, the Kotlin compiler generates a getter for our constant, which adds another...