Are you preparing for a Java interview? Then, you must practice java interview questions. Thus, you can get to know about the interview pattern and structure. It will boost your confidence and reduce your anxiety. If you are a fresher, then you can expect less tricky questions in interviews. It is time to check out some common Java interview questions for freshers.
How To Prepare For Java Interview Questions?
Are you going to sit for a Java interview? Then, it is obvious that you have solid knowledge in Java. However, you need to start brushing up your skills from many days before the interview.
Start your revision from the OOPs (Object-oriented programming System) concepts. It includes encapsulation, inheritance, data abstraction, and polymorphism.
Do not forget to revise data types as well as loops in Java. Many java interview questions for freshers can come from these concepts.
Brush up other concepts like synchronization, string handling, exception handling, etc. Besides, multithreading, generics, concurrent collection, etc. are also important.
Java Interview Questions & Answers
Can You Explain Java Programming Language In Brief?
Java is an object-oriented programming language. It is also a platform-independent, portable, and robust language. Sun Microsystems developed Java, which has numerous applications in the real world.
Is Java A Fully Object-Oriented Language?
No! It is because eight primitive data types in Java do not work as objects. These data types are byte, float, long, Boolean, double, short, char, and int.
Why Do You Consider Yourself A Competent Java Programmer?
State your strengths in Java. You can also mention achievements (if any) in your academic career, such as research papers on Java, etc. Also, state your speed and accuracy in coding.
Is Java Platform Independent? If Yes, Then Why?
Yes, Java is a platform-independent language. It is because the byte codes of Java can run on all machines regardless of the OS.
Why There Is No Concept Of Pointers In Java?
It is one of the common Java interview questions. There is no use of pointers in Java. It is because pointers are nor safe. Moreover, they make coding complicated. Java is a simple programming language. Pointers will change the definition of simplicity. To make the memory directly inaccessible to users, Java does not use pointers.
What Is OOPS?
“OOPs” stands for Object-oriented programming Systems. It is an approach in which programs revolve around objects. This strategy controls objects rather than logic. OOPs is a perfect programming approach for complicated and large programs. Moreover, programs that need frequent updates should also make use of OOPs.
Inheritance is a major concept in Java. It allows inheritance of the one class’s properties by another. Moreover, inheritance also enables programmers to reuse the Java codes and connects various classes. There are two types of classes under the concept of inheritance. One is the parent class or base class. The other is child class or derived class.
Parent class allows a child class to inherit its properties.
What Do You Mean By Polymorphism?
Polymorphism is one of the key concepts of OOPs. It can allocate a different usage or meaning to a specific entity. Such entities can be an object, a variable, or a function. Owing to polymorphism, they can take multiple forms.
Polymorphism is of two types.
Run time polymorphism
The former one is method overloading. And the later one makes use of the interface as well as inheritance.
Can You Name And Brief The Inheritance Types In Java?
Four types of inheritances are there in Java. They are single inheritance, multilevel inheritance, hierarchical inheritance, and hybrid inheritance.
It is time to take a look at them in brief:
Single inheritance is a straightforward concept. One base class and one derived class are there. Here, the derived class can inherit the properties of the base class.
Multilevel inheritance allows a class to inherit properties from a class, which is also a derived class. That means this type of inheritance will have one class with multiple base classes. However, the base classes are present at various levels.
This type of inheritance comprises multiple derived classes but with the same base class.
It is an amalgamation of two or more kinds of inheritance.
What Are The Key Concepts Of OOPs?
There are four key concepts of OOPs:
Encapsulation: It is an approach in Java to bundle the data as well as code together. As a result, they become a single unit.
Inheritance: This property allows one class (child class) to inherit the properties of another class (parent class).
Polymorphism: It is an ability that allows an object, function, or variable to take different forms.
Abstraction: It is a concept to conceal all the details of implementation from users. Instead, it only offers functionalities to them.
Define An Association In Java.
Association is nothing but a relationship in which every object has its lifecycle. Moreover, no owner is present there.
For example, there are multiple teachers and multiple students in a school. One student can associate with more than one teacher. Moreover, more than one student can associate with one teacher. However, no ownership is there between the multiple objects. And all of them have individual lifecycles.
The relationship between the objects can be of many types. They are one to one, many to one, and one to many.
Now, you are familiar with various java interview questions. It is time to start your preparation in full swing. Do not forget to practice coding on different programming questions. Interviewers will judge your practical coding skills more than theoretical knowledge.
Moreover, you need to improve your coding speed to stand out from others. Also, a theory question can come to you with the need for a coding explanation.
Check out the online forums if you develop queries during your preparation.
In short, you need to gear your Java skills up as much as possible.
Be positive and hope for the best!