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64 lines
1.3 KiB
64 lines
1.3 KiB
2 years ago
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# Circle
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### Instructions
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Create a class named `Circle`.
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Its attributes:
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- x - `double`
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- y - `double`
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- radius - `double`
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- getters:
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- area
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- perimeter
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- rightMostCoordinate (x axis)
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- leftMostCoordinate (x axis)
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- highestCoordinate (y axis)
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- lowestCoordinate (y axis)
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- Constructor:
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- x - `required`
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- y - `required`
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- radius - `required`
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### Getters and setters
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To work with objects, either getting some information or changing it, we should use methods as it might not be a good idea to directly change objects fields.
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An example of this principle is hunger - you should not change person's hunger level directly, but feed them instead. Since it is common to set or get these values, we use getters and setters in OOP.
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In Dart, when you specify getters and setters, you must treat them as **fields**.
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Syntax of the getters and setters:
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```dart
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class Rectangle {
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double l, t, w, h;
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Rectangle(this.l, this.t, this.w, this.h);
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double get right => this.l + this.w;
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set left(double value) {
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if (value >= 0) {
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this.l = value;
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} else {
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throw new FormatException();
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}
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}
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double get bottom => this.t - this.h;
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}
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void main() {
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var rect = Rectangle(3, 4, 20, 15);
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rect.left = 12;
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print(rect.l);
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}
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```
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- Note: Do not use math library, pi = 3.14
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