OOPS Interview Question in Java:-
OOP's is the most important topic of the interview, especially for JAVA.
I am providing some most important interview questions based on OOP'S.
1) What is OOPS?
2) Why we use OOP'S technique in programming?
3) What is the full form of OOP'S?
4) What is the definition of Object, Class depends on object or Object is depend on class?
5) What is the difference between Object and Instance(reference)?
6) What is the Garbage collector in Java, how it works?
7) What are the Access modifier(Access Control, Access Specifier) and non-access modifiers in Java?
8) What is an immutable object in Java?
9) What is Singleton class, Concreate class, Inner class in Java?
10) What is the final class, the final method, and the final variable in Java?
11) What is another way to protect class from an inheritance except for the final class?
12) What is init block, static block, and constructor, if all three present then what will be the execution process?
13) What is the difference between abstract class and interface?
14) what component can be defined under the interface?
15) How to restrict the class to create only three objects?
16) why Java does not support operator overloading?
17) tell the name of five predefine final class?
18) Java Support multiple inheritances or not? if not support then why, if support then how?
19) What is getInstance(), toString(), equals() in Java?
20) What is data abstraction, how to implement it into the Java Program Code?
21) What are the IS-A and HAS-A relationships in Java?
22) What is Composition, Aggregation, and Association in Java?
23) What is static binding and dynamic binding?
24) What is a Generic class in Java?
25) What is Anonymous class and Anonymous Object in Java?
If you want to show MOCK Interview of Java then watch this video session:-
Q:- What is oops?
ردحذفOOPS stands for Object oriented program structure.
Procedural Programming is About Writing Procedures or methods that perform operations on the data, while object oriented programming is about creating object that contain both data and methods.
Q:- Why we use OOP'S technique in programming?
ردحذفIt is used to create real world based application using dynamic memory allocation security,reusability and extend-ability features.
Q:- What is the full form of OOP'S?
ردحذفOOP'S full form is OBJECT ORIENTED PROGRAMMING STRUCTURES.
Q:-What is the definition of Object,Class depends on object or Object is depend on class?
ردحذفObject:- It is a real-world entity that has an identity,state and behavior.
Example:- Electronics is the class Such as Latop,Mobiles,Televison,camera etc.
Q:- What is the difference between Object and Instance(reference)?
ردحذفAn instance is a specific representation of an object.An object is a generic thing while an instance is a single object that has been created in memory.Usually an instance will have values assigned to it's properties that differentiates it from other instances of the type of object.
Q:- What is the Garbage collector in Java, how it works?
ردحذفGarbage collector is the process by which programs perform automatic memory management. java program compile to byte code that can be run on a java virtual machine or JVM for short when java program run on the JVM. the garbage collector finds these unused objects and deletes them to free up memory.
Java garbage collector is an automatic process. the programmer does not need to explicity mark object to be delete.the garbage collection implemention lives in the jvm.
Q:-What are the Access modifier(Access Control, Access Specifier) and non-access modifiers in Java?
ردحذفThere are two types of modifiers in java access modifier and non access modifiers
The access modifire in java specifies the accessibility or scope of a feilds, constructorpr class. we can change the access level of field,constuctor,methods,and class by applying the access modifier on it.
There are four types of java access modifier private,default,protected and public.
There are many non-access modifiers,such as static,abstract,synchronized,native,volatile,transient,etc.
Q:- What is an immutable object in Java?
ردحذفAn immutable object is an that will not change its internal state after creation.
Immutable object are very useful in multithreaded application because they can be shared between threads with out sychronization.
Q:- What is Singleton class, Concreate class, Inner class in Java?
ردحذفConcreate class:- It is the class which is used to implement the functionality of abstract class a concreate class.
It is similar to a normal class but it will be associated with the interface method and abstract class method.
Inner class:- Using this concept we will create class inside class.It is also called nested class.