RulesAndPropertiesOfConstructor.txt

RULES:


    1.A Constructor cannot have a return type.

    2.A constructor must have the same name as that of the Class.

    3.Constructors cannot be marked static

    4.A constructor cannot be marked abstract

    5.A Constructor cannot be overridden.

    6.A Constructor cannot be Final.

PROPERTIES:

    1.A constructor is invoked when a new object is created.

    2.Constructors can also be overloaded but it can not be overridden.

    3.Every class has at least one constructor. If a user doesn’t provide any, JVM will provide a default no-arg constructor.

    4.Abstract class also has a constructor.

    5.A constructor must have the same name as the class.

    6.A constructor can’t have a return type.

    7.If a method with the same name as a class has return type will be treated as a normal member method and not constructor.

    8.A constructor can have any access modifier(All).

    9.A default constructor is a no-arg constructor which calls the no-arg constructor of the superclass. In case superclass doesn’t have any no-arg constructor then it will throw a runtime exception.

    10.In a case where a class has the default constructor, its superclass needs to have a no-arg constructor.

    11.The first statement of a constructor can be either this or super but cannot be both at the same time.

    12.If the coder doesn’t write any this or super call then the compiler will add a call to super.

    13.Instance member can be accessible only after the super constructor runs.

    14.Interfaces do not have constructors.

    15.A constructor is not inherited. Hence cannot be overridden.

    16.A constructor cannot be directly invoked. It will be invoked(Implicitly) when a new object is created or a call by other constructors.