8.9. Structures as return typesΒΆ
You can write functions that return structures. For example,
findCenter takes a Rectangle as an argument and returns a
Point that contains the coordinates of the center of the
Rectangle:
Point findCenter (Rectangle& box) {
double x = box.corner.x + box.width/2;
double y = box.corner.y + box.height/2;
Point result = {x, y};
return result;
}
To call this function, we have to pass a box as an argument (notice that
it is being passed by reference), and assign the return value to a
Point variable:
Rectangle box = { {0.0, 0.0}, 100, 200 };
Point center = findCenter (box);
printPoint (center);
The active code below uses the findCenter function. Run the code
to see what the output is!
The output of this program is (50, 100).
addTwo,printPoint,findCenter-
Look at the return type, found before the function name in its definition.
printPoint,findCenter-
Look at the return type, found before the function name in its definition.
addTwo,findCenter-
Correct!
Point,Rectangle-
These are structures, not functions.
Q-2: Which functions will return a structure?
struct Point {
double x, y;
};
struct Rectangle {
Point corner;
double width, height;
};
Rectangle addTwo (Point& p) {
double x = p.x + 2;
double y = p.y + 2;
Point result = {x, y};
return result;
}
void printPoint (Point p) {
cout << "(" << p.x << ", " << p.y << ")" << endl;
}
Point findCenter (Rectangle& box) {
double x = box.corner.x + box.width/2;
double y = box.corner.y + box.height/2;
Point result = {x, y};
return result;
}
int main() {
Rectangle box = { {0.0, 0.0}, 100, 200 };
Point center = findCenter (box);
cout << addTwo (center) << endl;
printPoint (center);
}