Functions nesting

Question

I'm taking the online course "Programming Methodology" available on iTunes U. The course has an introduction with "Karel the robot" based on Java and it raised a question for me. Take for example this code :

import stanford.karel.*;

public class MidpointFindingKarel extends SuperKarel {

    // You fill in this part
    public void run(){
        fillBeepers();
        turnAround();
        move();
        checkWestEdge();


    }
    private void fillBeepers(){
        move();
        while(frontIsClear()){
            putBeeper();
            move();
        }
    }
    private void checkEastEdge(){
        while(beepersPresent()){
            move();
        }
            if(noBeepersPresent()){
                turnAround();
                move();
                if(beepersPresent()){
                    pickBeeper();
                    move();
                    checkWestEdge();
                }
                else putBeeper();
            }
    }
    private void checkWestEdge(){
        while(beepersPresent()){
            move();
        }
            if(noBeepersPresent()){
                turnAround();
                move();
                if(beepersPresent())
                {
                    pickBeeper();
                    move();
                    checkEastEdge();
                }
                else putBeeper();
            }
    }
}

The idea of this code is to find the middle of the screen by putting "beepers" all over besides the edges, and then taking the edges of the beeper. What I've done is making each "finding edge" function to call the other function to find the other edge. It eventually reaches a point where its in the middle and it checks for beepers to the left and right, see there are none, and place one in the middle.

Now I wanted to ask: I tend to nest functions (Or methods? How ever you call them) very often. Is it a bad habit as a programmer and at larger and more complex projects it'll get back at me? Does it reduce the readability of my code? If so, could anyone provide a solution how to call these functions?

Answer 1

calling methods from other methods is not only acceptable practice, it is godd one as well. (reusing code is good practice). however, in your code, check west and check east are mostly duplicate. I would structure it like this

private void checkEdge(String orientation){
    while(beepersPresent()){
        move();
    }
        if(noBeepersPresent()){
            turnAround();
            move();
            if(beepersPresent()){
                pickBeeper();
                move();
                orientation = orientation.equals("west") ? "east" : "west";
                checkEdge(orientation);
            else putBeeper();
        }
}

that way you have one method that check edges and is capable of checking west and east