Adding methods to a point class

[P Derlyuk]

I am having trouble getting started on this practice problem. Any help would be great!


Add the following method to the Point class:

public int manhattanDistance(Point other)

Returns the "Manhattan distance" between the current Point object and the given other Point object. The Manhattan distance refers to how far apart two places are if the person can only travel straight horizontally or vertically, as though driving on the streets of Manhattan. In our case, the Manhattan distance is the sum of the absolute values of the differences in their coordinates; in other words, the difference in x plus the difference in y between the points.

public class Point {
    private int x;
    private int y;
    
    // your code goes here
    
}

[Bear Bibeault]

Where's your try at the code? What specific problems are you having with it?

[P Derlyuk]

Honestly, I'm not even sure where to begin.

[Bear Bibeault]

Start by adding an empty method with the specified signature. Then it can start to be filled out; one step at a time.

[P Derlyuk]

Ok, i tried this and am getting a StackOverflowError.

private int x1;
private int y1;
Point p = new Point(x1, y1);
public int manhattanDistance(Point p){
    
    int x_diff = Math.abs(x1 - x);
    int y_diff = Math.abs(y1 - y);
    int final_dist = xdiff + ydiff;
    return final_dist;
}

[Jeff Verdegan]

P Derlyuk wrote:Ok, i tried this and am getting a StackOverflowError.

Then some method or constructor is calling itself endlessly. It's somewhere in the code you haven't shown. However, if that's a piece of your Point class, then this line:

Point p = new Point(x1, y1);  

is the cuprit.

It's called every time the enclosing class (Point, I assume) is instantiated. And it instantiates a Point, which, if this is part of the Point class, executes that line again, and so on.

Why do you have a Point object containing another Point object?

[P Derlyuk]

I figured it out. I over complicated it at first. here is what i think it should be.

public int manhattanDistance(Point other){
     int x_diff = Math.abs(other.x - this.x);  
     int y_diff = Math.abs(other.y - this.y);  
     int final_dist = x_diff + y_diff;  
     return final_dist;  
}