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Inheritance interview questions and answers in java

Inheritance is one of the oops concept. If any interview you have attended on java developer there must and should be inheritance related questions you will face it. So, here are few of the inheritance questions and answers. If any one of you people are facing more than these interview questions, share with me through "contact me here" gadget or drop me an email to "subbareddynallamachu@gmail.com".

Q1: What is Inheritance in java?
A: Deriving new class from existing classes such that the new classes acquire all the features of existing classes is called inheritance.

Q2: Why super class members are available in sub class?
A: Because, Sub class object contains a copy of Super class object.

Q3: What is the advantages of inheritance?
A: Inheritance main use is, a programmer reuses the super class code without rewriting it, in creation of sub classes. So, developing classes becomes very easy. Hence, the programmers productivity is increased.

Q4: What is the use of super key word in java?
A: Mainly we will use the super keyword for accessing the super class member or method, when the both have the same name in super class and sub class.

For Ex: If i have declared a method as show() in super class and also i have declared same method name in sub class. In that scenario I need to execute the super class method into sub class, we will use super keyword.

                  super.show();

Q5: What all the types of inheritance in java?
A: Mainly we have two types of inheritances in java. That are,
                        1. Single Inheritance
                        2. Multiple Inheritance

         By the combination of these inheritances we have some other types of inheritances called,
                      1. Multi-level Inheritance
                      2. Hierarchical Inheritance
                      3. Hybrid Inheritance

Note: In Java Multiple Inheritance not supported between the classes in java. For avoiding these problem in java introduced new concept called Interfaces.

Q6: Why multiple inheritance is not available in java?
A: Multiple inheritance is not available in java because of the following reasons.
  1. It leads to confusion for a java program.
  2. The programmer can achieve multiple inheritance by using interfaces.
  3. The programmer can achieve multiple inheritance by repeatedly using single inheritance.
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