dart_basics/lib/basic_part3.dart

import 'dart:math';

void basic_operators() {
  print("\nDart Operators:");
  // Type test operators
  double n = 1.1;
  print((n as num).toString());
  print(n is! int);
  print(n is double);

  var a = Account(username: 'Bobson');
  print(a);

  var b = Account();
  b?.username = "I'm Groot";
  print(b);

  var list = List()
    ..insert(0, 123)
    ..add(456)
    ..addAll([789, 111]);
  print(list);
}

class Account {
  String username;
  String password;

  Account({username, password})
    : this.username = username,
      // this.password = (password != null) ? password : 'AutomaticallyGenerateSecretPassword';
      this.password = password ?? 'AutomaticallyGenerateSecretPassword';

  @override
  String toString() {
    return "Account($username, $password)";
  }
}

void basic_classes() {
  print("\nDart Classes:");
  // Point Class from dart:math
  var p1 = Point(1, 2);
  var p2 = Point(3, 4);
  print("p1: $p1, p2: $p2");
  print(p1.distanceTo(p2));
  print(p2.magnitude);

  // Complex Number (複數) - x + yi (i = √-1)

  // 0 + 0i
  var c1 = BaseComplex();
  c1.real = 5;
  c1.imaginary = 2;
  print(c1.runtimeType);

  var c2 = BaseComplex()
    ..real = 5
    ..imaginary = 2;
  print("c1: $c1, c2: $c2");

  print(c1 == c2);

  // With Constructor
  var c = Complex(5, 2);
  var r = Complex.real(10);
  var i = Complex.imaginary(-5);
  print("c: $c, r: $r, i: $i");
}

class BaseComplex {
  num real;
  num imaginary;

  @override
  bool operator ==(dynamic other) {
    if (other is! BaseComplex) {
      return false;
    } else {
      return real == other.real && imaginary == other.imaginary;
    }
  }

  // @override
  // String toString() {
  //   if (imaginary >= 0) {
  //     return "$real + ${imaginary}i";
  //   } else {
  //     return "$real - ${imaginary.abs()}i";
  //   }
  // }

  // @override
  // String toString() => "${this.runtimeType}($real, $imaginary)";
}

class Complex {
  // Private property(member)
  num _real;
  num _imaginary;

  // Getters & Setters
  get real => _real;
  set real(num newReal) => _real = newReal;

  get imaginary => _imaginary;
  set imaginary(num newImaginary) => _imaginary = newImaginary;

  // Traditional way
  // Complex(num real, num imaginary) {
  //   this.real = real;
  //   this.imaginary = imaginary;
  // }

  // Syntactic sugar
  Complex(this._real, this._imaginary);

  // Named Constructor
  // Complex.real(num real) {
  //   this.real = real;
  //   this.imaginary = 0;
  // }
  Complex.real(num real) : this(real, 0);

  Complex.imaginary(num imaginary) : this(0, imaginary);

  @override
  bool operator ==(dynamic other) {
    if (other is! Complex) {
      return false;
    } else {
      return real == other.real && imaginary == other.imaginary;
    }
  }

  @override
  String toString() {
    if (imaginary >= 0) {
      return "$real + ${imaginary}i";
    } else {
      return "$real - ${imaginary.abs()}i";
    }
  }
}