Constructors in DART language

In this article, I am going to explain about constructors in dart language.
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Constructors in Dart

A  constructor is a class member function in dart language   that has same name class itself. Constructors does not inherited by  sub class.

Example of constructor

class Construct{


    print("Wecome in Dart Constructor !");


  Construct.MyConstruct1(String s){

    print("Wecome in Parametrized Constructor !");



void main()


  Construct obj = new Construct.MyConstruct();

  Construct obj1 = new Construct.MyConstruct1("Dart");



Constructor are different types

  • Default constructor

    The default constructor is also know as no argument constructor, if you do not declare a default constructor, it is automatically created.

Example of default constructor

class DefaulConstruct{

  DefaulConstruct() {

  print("I am a Default Constructor");}


void main() {

  DefaulConstruct obj = new DefaulConstruct();



  • Named constructor

    You can used named constructor to implement multiple constructor for a class.

  • Factory constructor

    factory constructor is used, when we want to create a instance only once; and use this instance for multiple time.

  • Constant constructor

    An immutable compile time constant object is known as a const object; and constant constructor is used for it.

Example of constant constructor

class constcon{

  final int a;

  const constcon(this.a);



  var a = const constcon(1);

  var b= const constcon(1);

  print("The value of with const constructor is ${a==b}");

   /********And if you check without const **************/

   var c = new constcon(1);

   var d = new constcon(2);

   print("The value of WithOut const constructor is ${c==d}");



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