DART

class in dart

class class_name {  
	//rest of the code here:
}

dart class

class Car {  
   // field 
   String engine = "E1001";  
   
   // function 
   void disp() { 
      print(engine); 
   } 
}

dart class sample

class Spacecraft {
  String name;
  DateTime? launchDate;

  // Read-only non-final property
  int? get launchYear => launchDate?.year;

  // Constructor, with syntactic sugar for assignment to members.
  Spacecraft(this.name, this.launchDate) {
    // Initialization code goes here.
  }

  // Named constructor that forwards to the default one.
  Spacecraft.unlaunched(String name) : this(name, null);

  // Method.
  void describe() {
    print('Spacecraft: $name');
    // Type promotion doesn't work on getters.
    var launchDate = this.launchDate;
    if (launchDate != null) {
      int years = DateTime.now().difference(launchDate).inDays ~/ 365;
      print('Launched: $launchYear ($years years ago)');
    } else {
      print('Unlaunched');
    }
  }
}

dart class and object

// Class Declaration 
class AClass {}

void main() {
  // Object creation
  var a = AClass();

  // Access Object property
  print(a.hashCode);
  print(a.runtimeType);
  
  // Access String Object method
  print("vel".toUpperCase());

  // Access int property
  print(2.isNegative);
  print(2.runtimeType);
  
}

dart class with

Mixins are a way of reusing a class’s code in multiple class hierarchies.

To use a mixin, use the with keyword followed by one or more mixin names. The following example shows two classes that use mixins:

class MyClass with MyMixin {
  // ···
}

To implement a mixin, create a class that extends Object and declares no constructors. 
Unless you want your mixin to be usable as a regular class, use the mixin keyword instead of class. 
For example:

mixin MyMixin {
  // ···
}

Dart class structure

class Person {
  String name = 'Lara';
  int age = 12;
  
  Person({this.name = '',  this.age = 18});
  
}


int addNumbers(int num1, int num2) {
  return num1 + num2;
}

void main() {

  var p1 = Person(name: 'Gabriel', age: 18);
  var p2 = Person(name: 'Clara', age: 29);
  
  print({'name': p1.name, 'age': p1.age});
  print({'name': p2.name, 'age': p2.age});
    
  
}