feat: Finish part - 5

bin/main.dart

@@ -2,6 +2,7 @@ import 'package:dart_basics/basic_part1.dart' as part1;
 import 'package:dart_basics/basic_part2.dart' as part2;
 import 'package:dart_basics/basic_part3.dart' as part3;
 import 'package:dart_basics/basic_part4.dart' as part4;
+import 'package:dart_basics/basic_part5.dart' as part5;
 
 main(List<String> arguments) {
   // Part 1
@@ -18,4 +19,8 @@ main(List<String> arguments) {
 
   // Part 4
   part4.basic_classes();
+
+  // Part 5
+  part5.basic_classes();
+  part5.basic_interfaces_and_mixins();
 }

lib/basic_part5.dart

@@ -0,0 +1,136 @@
+import 'dart:math';
+
+void basic_classes() {
+  Square square = Square(10.0);
+  Rectangle rectangle = Rectangle(20.0, 15.0);
+  Circle circle = Circle(2.0);
+
+  print(square.name);
+  print(rectangle.name);
+  print(circle.name);
+}
+
+abstract class Shape {
+  double get perimeter;
+  double get area;
+  String get name;
+}
+
+class Circle extends Shape {
+  double radius;
+
+  Circle(this.radius);
+
+  @override
+  double get area => pi * (radius * radius); // πr²
+
+  @override
+  String get name => "I'm a circle with radius: $radius";
+
+  @override
+  double get perimeter => 2 * pi; // 2πr
+
+  @override
+  String toString() => "${this.runtimeType}($radius)";
+}
+
+class Rectangle extends Shape {
+  double length;
+  double width;
+
+  Rectangle(this.length, this.width);
+
+  @override
+  double get area => length * width;
+
+  @override
+  String get name => "I'm a rectangle with length: $length, width: $width";
+
+  @override
+  double get perimeter => 2 * (length + width);
+  
+  @override
+  String toString() => "${this.runtimeType}($length, $width)";
+}
+
+class Square extends Rectangle {
+  Square(double side) : super(side, side);
+
+  @override
+  String get name => "I'm a square with side: $length";
+}
+
+
+void basic_interfaces_and_mixins() {
+  SmartPhone myPhone = SmartPhone("123-456-789");
+  SmartTablet myPad = SmartTablet("111-222-333");
+
+  try {
+    myPhone.pickUp();
+    myPhone.dial("789-456-123");
+    myPad.pickUp();
+    myPad.dial("789-456-123");
+  } catch (e) {
+    print(e);
+  }
+
+  print(myPhone.nowTime);
+  myPhone.setAlarm(myPhone.nowTime.add(Duration(minutes: 20)));
+}
+
+mixin ClockMixin {
+  DateTime nowTime = DateTime.now();
+
+  void setAlarm(DateTime alarmTime) {
+    print("Set an alarm at $alarmTime");
+  }
+}
+
+/// Interface Phone
+abstract class Phone {
+  String get phoneNumber;
+
+  void dial(String number) {}
+
+  void pickUp() {}
+}
+
+class SmartPhone with ClockMixin implements Phone {
+  String _phoneNumber;
+
+  SmartPhone(String phoneNumber) : this._phoneNumber = phoneNumber;
+
+  @override
+  void dial(String number) {
+    print("SmartPhone($phoneNumber) dials $number");
+  }
+
+  @override
+  String get phoneNumber => _phoneNumber;
+
+  @override
+  void pickUp() {
+    print("Pick up SmartPhone($phoneNumber)");
+  }
+}
+
+class SmartTablet with ClockMixin implements Phone {
+  String _phoneNumber;
+
+  SmartTablet(String phoneNumber) : this._phoneNumber = phoneNumber;
+
+  @override
+  void dial(String number) {
+    throw UnimplementedError("SmartTablet can't dial");
+  }
+
+  @override
+  String get phoneNumber => _phoneNumber;
+
+  @override
+  void pickUp() {
+    print("Pick up SmartTablet($phoneNumber)");
+  }
+}
+
+