Dart Super Constructor

The child class can inherit all properties (methods, variables) and behavior of parent expect parent class constructor.& The superclass constructor can be invoke in sub class by using the super() constructor. We can access both non-parameterized and parameterized constructor of superclass. Accessing the constructor of superclass is slightly different in the Dart. The syntax is given below.

Syntax:

Implicit super

As we know that the constructor is automatically called when we instantiate a class. When we create the object of sub class, it invokes the constructor of sub class which implicitly invokes the parent class’s default(non-parameterized) constructor. We can use super() constructor in our subclass to invoke superclass constructor. Let’s understand the following example.

Example –

Output:

Dart Implicit Superclass constructor example  This is a superclass constructor  This is a subclass constructor  Welcome to Tutor Aspire  

Explicit super

If the superclass constructor consists of parameters then we require to call super() constructor with argument in to invoke superclass constructor in subclass explicitly. Let’s understand the following example.

Example –

Output:

Dart explicit Superclass constructor example  This is a parameterized superclass constructor  We are calling superclass constructor explicitly  This is a subclass constructor  Welcome to Tutor Aspire  

Example – 2