Below is a collection of commonly asked Java Interview questions and answers. The Java interview questions and answers are brief and precise.
Table of Contents
1. What is Java?
Java is a high-level, object-oriented, reliable, secure, high-performance, multithreaded, and portable programming language. It is also platform-independent. In June 1991, James Gosling created it. Because it offers its own JRE and API, it may also be referred to as the platform.
2. What are the differences between Java and C++?
|Java is platform-independent.||C++ is platform-dependent.|
|The primary usage of Java is application programming. Its usage of it is widespread in desktop, web-based, business, and mobile applications.||The majority of system programming is done in C++.|
|Goto statement functionality is not available in Java.||The goto statement is supported by C++.|
|Java does not allow class-based multiple inheritance. Interfaces in Java are capable of doing that.||Multiple inheritance is supported in C++.|
|Operator overloading is not supported by Java.||In C++, operator overloading is supported.|
|Internally, Java supports pointers. The pointer program, however, cannot be created in Java. This indicates that Java only supports certain types of pointers.||There are pointers in C++. In C++, pointer programs are possible.|
|Java only allows calls with values. Java does not support calls by reference.||Both call by value and call by reference are supported in C++.|
|Unions and structures aren’t supported in Java.||Unions and structures are supported in C++.|
|Java provides built-in support for threads.||There is no built-in thread support in C++. In order to support threads, it uses third-party libraries.|
|Java doesn’t interface with hardware as much.||Better suited to hardware is C++.|
3. Describe the Java programming language’s features.
The Java programming language has the following characteristics.
- Simple: It’s simple to learn Java. Because Java’s syntax is based on C++, writing programs in it is simpler.
- Object-Oriented: Because Java adheres to the object-oriented paradigm, we may retain our code as a collection of various types of objects that include both data and behavior.
- Portable: Java allows for a read-once, write-anywhere architecture. On any system, the Java application may be run. Java programs (.java) are transformed into executable bytecode (.class), which may be used on any system.
- Platform Independent: Programming in Java is platform independent. When compared to other programming languages like C and C++, it does not need a platform to run. Java comes with a platform that is used to run its programs. Java may be run independently of an operating system.
- Secured: Because Java doesn’t utilize explicit pointers, it is safe. Java is made more secure with the addition of the ByteCode and Exception handling concepts.
- Robust: Java utilizes good memory management, making it a powerful programming language. It is more resilient because of features like automatic garbage collection and exception handling, etc.
- Interpreted: Java executes programs using a Just-in-time (JIT) interpreter and a compiler.
- High Performance: Because Java bytecode is “near” to native code, it runs more quickly than other conventionally interpreted programming languages. It is still somewhat slower than a compiled language (like C++), for example.
- Multithreaded: Java applications may handle numerous tasks at once by using multiple threads. The fundamental benefit of multi-threading is that each thread doesn’t take up memory. It has a shared memory space. For multimedia, Web applications, etc., threads are crucial.
- Distributed: Due to its ability to let users construct distributed applications, Java is distributed. Applications for networked computing are developed using RMI and EJB. We may access files by calling the methods from any computer connected to the internet thanks to a feature of Java.