Why parameterized constructor is used Parameterized constructor is used to provide the initial values to the object properties (initial state of object). The name of a parameter must be unique in its scope. A constructor with one or more parameters is called as parameterized constructor. One more point to add here is that super() call is automatically added by the java compiler, if doesn’t find super() in derived class. This name is used within the method body to refer to the passed-in argument. While non-arg constructor is defined by a programmer only.
Inside the constructor we set x to y (xy). The following example adds an int y parameter to the constructor. This default constructor calls its parent class’s non-parameterised constructor It initializes class variables to their default values.Ĭlass Derived extends Base // Default constructor of class "Derived" will automatically calls non-arg constructor of class "Base" and intialzes value to the variables Constructors can also take parameters, which is used to initialize attributes. Previous Next Courses Downloads About Us Contcat Us. But it cannot because there is no perameterless constructor in Address. The parameterized constructor of parent class must be called explicitly using the super keyword. In the constructor of EmployeeAddress java tries to call for a parameterless constructor of Address since Address is a parent class.
Parameterized constructor in java code#
If not declared explicitly, java compiler provides a non-parameterised constructor, i.e, default constructor. The problem with your code is that class Address does not have a default constructor defined. It is used to initialize the instance variables of an object with specific values. While Test() constructor will further find and call non-arg constructor of JFrame class(Parent) and so onĮvery class must have at least one constructor. A parameterized constructor is a constructor that takes one or more arguments. The parameter values of the constructor are. Reference variable cFrame will call non-arg constructor Test(), not default constructor. When any constructor is declared with one or more parameters, then it is called a parameterized constructor.
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