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Interview Questions and Answers for 'Ultramain' - 3 question(s) found - Order By Newest | ||||
Very Frequently asked to fresh graduates and less experienced. Favorite question in Walk in drives. Frequently asked in Indian Services companies. | ||||
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Ans. Overloading - Similar Signature but different definition , like function overloading. Overriding - Overriding the Definition of base class in the derived class. | ||||
Sample Code for overloading Sample Code for overriding | ||||
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Like Discuss Correct / Improve  java   oops   overloading   overriding   oops concepts   basic interview question   overloading vs overriding Asked in 86 Companies basic   frequent | ||||
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Related Questions | ||||
What are the difference between composition and inheritance in Java? | ||||
Explain OOPs or Explain OOPs Principles or Explain OOPs Concepts or Explain OOPs features or Tell me something about OOPs | ||||
What is the difference between Encapsulation and Abstraction? | ||||
What are points to consider in terms of access modifier when we are overriding any method? | ||||
What is Polymorphism in Java ? | ||||
Can you give a real world example of Encapsulation and Abstraction ? | ||||
Why every object constructor automatically call super() in Object before its own constructors? | ||||
How compiler handles the exceptions in overriding ? | ||||
Difference between Composition and Inheritance ? | ||||
Usually asked in relation to casting and ClassCastException. | ||||
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Ans. The operator instanceOf is used to verify if the specified object is the instance of specified class or interface. Syntax if(x instanceOf ABC) where x is an object reference and ABC could be a class name or interface name. The above statement will be true if x holds an object that is an instance of ABC or any of the child class of ABC or if x holds an object that implements ABC. instanceOf operator is used to verify in case of downcasting. For ex - DerivedClass extends BaseClass x is the reference of BaseClass but holds DerivedClass object ( Polymorphism ) There is an operation that is defined in Derived Class, let's say derivedClassMethod() We cannot call derivedClassMethod() directly using x as x is reference of BaseClass and not DerivedClass and hence can only access methods that are defined in BaseClass and overridden in derived class. Though we can cast it to DerivedClass as following ((DerivedClass)x).derivedClassMethod(); But it may throw ClassCastException in case x doesn't hold an instance of DerivedClass at that point. So before casting it to DerivedClass we may like to make sure that it is an instance of DerivedClass and hence won't throw ClassCastException. So we make a check for it if(x instanceOf DerivedClass) { ((DerivedClass)x).derivedClassMethod(); } | ||||
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Like Discuss Correct / Improve  instanceOf  instanceOf operator  Why we need instanceOf operator  use of instanceOf operator Asked in 2 Companies Intermediate   frequent | ||||
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In which cases isn't instanceof operator a bad practice? | ||||
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Ans. An Exception in java is the occurrence during computation that is anomalous and is not expected. Exception handling is the mechanism which is used to handle such situations. | ||||
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Like Discuss Correct / Improve  exception handling Asked in 18 Companies basic   frequent | ||||
Related Questions | ||||
What are the ways to avoid LazyInitializationException ? | ||||
How compiler handles the exceptions in overriding ? | ||||
What things should be kept in mind while creating your own exceptions in Java? | ||||
Difference between Checked and Unchecked exceptions ? | ||||
Explain java.lang.OutOfMemoryError ? | ||||
When do you get ClassCastException? or What is ClassCastException ? | ||||
If you are given a choice to implement the code to either Insert a Record or Update if already exist, Which approach will you follow ? | ||||
Explain throw, throws , try and catch in Java ? | ||||
What is ConcurrentModificationException ? | ||||
What will happen if we don't have termination statement in recursion ? | ||||