IFD:EAI SoS21/course material/Session 3: File Structuring, Pointers and Addresses

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Homework/Recap from Session 2:

Here are the solutions of last week's task. Please try a little to solve on your own, before you peek in here! :)

Distance Function Complete Code

To get the distance between two points on a 2D plane we can use the Pythagorean theorem as depicted in the picture below. We give coordinates to the points and use the coordinates to calculate the distance according to the formula c = sqrt( (x2-x1)^2 + (y2-y1)^2 ), where c is the distance between the two points.

Distance calc.png

To get the x- and y-coordinates in our code, we can use the private variables for point p1 (_x and _y) and the member functions getX() and getY() for point p2. So the most crucial lines of code are:

float Point2D::calculateDistanceToOtherPoint(Point2D p2){
    float distance = sqrt( (p2.getX() -_x)*( p2.getX() -_x)+( p2.getY()-_y)*( p2.getY() -_y) ); 
    return distance;
}

Note that, for the sqrt() function to be known to the compiler, you need to include the math library with

#include <math.h>

File Structuring

Pointers and Addresses

https://replit.com/@abnutzer/PointersAndAdresses