How to draw PlantUML for chained method call

[ngdeqi]

Hi all, how should I draw a sequence diagram for the chained method call, nameList.getByIndex(2).getHeight() from Main?

public class Main {

    public static void main(String[] args) {
        NameList nameList = new NameList();
        int height = nameList.getByIndex(2).getHeight();
    }
}

public class NameList {
    :
    public Person getByIndex(int index) {
        : 
        return Person;
    }  
}

public class Person {
    :
    public int getHeight() {
        return this.height;
    }
}

I am not sure if getHeight() should be invoked by Main or NameList object.

[wcwy]

Hi, AFAIK, in nameList.getByIndex(2).getHeight(), essentially what it does is to call nameList.getByIndex(2) first, and on the object returned it calls getHeight() method.

You can picture nameList.getByIndex(2).getHeight() into something like this:

Person temp = nameList.getByIndex(2)
int height = temp.getHeight();

Since the method getHeight() is called on the object after the object is returned back to main(), the getHeight should be invoked by Main in sequence diagram.

[okkhoy]

Please take a look at the tutorial question that deals with this scenario.

[ngdeqi]

Thank you for the explanation! @wcwy