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Why do we assign a parent reference to the child object in Java?
salary is not accessible when the Child object is stored in a Parent reference. The answer is the intersection of “polymorphism” and “static typing”. Because Java is statically typed at compile time you get certain guarantees from the compiler but you are forced to follow rules in exchange or the code won’t compile.
What is a parent class?
Parent class is the class being inherited from, also called base class. Child class is the class that inherits from another class, also called derived class.
Can a child class have a child?
There is no limit to the number of children a class can have (but a child can have only one parent). Two children of the same parent are called siblings.
How to refer to parent and child classes in Java?
+ par.value); Output: If a parent reference variable is holding the reference of the child class and we have the “value” variable in both the parent and child class, it will refer to the parent class “value” variable, whether it is holding child class object reference.
Can a child class reference access a parent class reference?
The reference holding the child class object reference will not be able to access the members (functions or variables) of the child class. This is because the parent reference variable can only access fields that are in the parent class.
How are child and parent classes defined in PHP?
Let’s look at an example that spells out this relationship in detail, and starts to get into the object-oriented PHP code that defines parent and child classes. We’ll step through an example with one parent class, Dog, and two child classes, Catahoula_Dog and Golden_Retriever_Dog, giving code examples for each.
What does inheritance mean in object oriented programming?
In object-oriented programming, class inheritance refers to the ability of one class to extend —and be a child class of—another class. So right off the bat, here’s some language to get straight: If class Golden_Retriever extends class Dog, that means that class Golden_Retriever is a child class of class Dog .