Menu
I have a question about default constructors and inheritance in Java.
Generally, if you write a class and do not include any constructor, Java provides automatically for you a default constructor (one without parameters), which initializes all instance variables of the class (if there are any) with some default values (0, null, or false). If you write a constructor, however, with some parameters, and you don't write any default constructor, then Java does not provide a default constructor. My question is: what is the case with classes, which inherit from other classes - if I write a constructor with some parameters in them, but don't include a default constructor, do they inherit the default constructor of the super class?
417
What is a default constructor? A default constructor is a constructor created by the compiler if we do not define any constructor(s) for a class. Here is an example: public class Student { String firstName; String lastName; int age; public static void main(String args[]) { Student myStudent = new Student(); myStudent.
In java, by default, the Object class is the parent class. In Java inheritance is declared using the extends keyword. You declare that one class extends another class by using the extends keyword in the class definition.
No, constructors cannot be inherited in Java. In inheritance sub class inherits the members of a super class except constructors. In other words, constructors cannot be inherited in Java therefore, there is no need to write final before constructors.
The constructors have same name as their class and, have no return type. The default constructor in Java initializes the data members of the class to their default values such as 0 for int, 0.0 for double etc.
If you do not make a constructor, the default empty constructor is automatically created.
If any constructor does not explicitly call a super or this constructor as its first statement, a call to super() is automatically added.
Always.
62
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
