Today, nearly 10 million developers use the Java programming language. Programmers adopt it as one of the most extensively used programming languages. Hiring Java developers has become a difficult undertaking for enterprises due to increased competition. Only Java specialists with experience in developing, coding, implementing, and deploying a variety of applications are hired. Regardless of your coding abilities, passing the interview is essential if you want to land the Java job of your dreams. We’ve prepared a series of 10 of the most common Java Developer interview questions and model responses. Keep reading to see where you stand.
- Why isn’t Java a pure object-oriented programming language?
Java is not a pure object-oriented language because it supports primitive data types such as boolean, byte, short, char, int, float, long, and double.
- Is it possible to call Java an object-oriented programming language?
We are not mistaken if we declare that java is the entire object-oriented programming language. Because Java is built on the foundation of classes. By constructing objects, we can have access to this. However, we can say that java is not a totally object-oriented programming language because it includes primitive data types like float, char, int, boolean, double, and others. Is Java an object-oriented programming language in its purest form? Java is not a pure object-oriented programming language since it permits direct access to primitive data types. In addition, these primitive data types are unrelated to the Integer classes.
- Is it possible for you to distinguish between J2SDK 1.5 and J2SDK 5.0?
There isn’t much of a change between J2SDK 1.5 and J2SDK 5.0. The names of the versions have been altered by Sun Microsystems.
- What sets Java apart from C++?
Java is a compiled and interpreted language, whereas C++ is a compiled language only. They are different but there are similarities as well. C++ programs can only run on the machine where they were compiled, whereas Java apps can run on any machine. Users can utilize pointers in their programs in C++. Java, on the other hand, is unable to do so. Pointers are used in Java internally. In C++, multiple inheritances are supported; however, in Java, they are not. The aim is to avoid the complexity of name ambiguity leading to the diamond issue.
- Pointers are used in C and C++. Why doesn’t Java make use of pointers?
Beginner programmers should stay away from pointers since they are difficult to work with. Because Java emphasizes code simplicity, the use of pointers can be challenging. The use of a pointer may also result in errors. Furthermore, because pointers allow users to directly access memory, security is compromised when they are used. A certain level of abstraction is offered by not including pointers in Java. Additionally, the use of pointers may make garbage collection more time-consuming and inaccurate. Because references, unlike pointers, cannot be modified, they are utilized in Java.
- In ASCII, Unicode, UTF-16, and UTF-8, how many bits are required to represent ASCII, Unicode, UTF-16, and UTF-8 characters?
Unicode requires 16 bits. Despite the fact that ASCII requires just seven bits, it is typically stated as eight. Characters in UTF-8 are shown in patterns of 8, 16, and 18 digits. Patterns in UTF-16 must be 16 bits or larger.
- What are the default variables and instance values in Java?
Variables in Java are not given default values. We must first initialize the value before we can utilize it. A compilation error will be used if this is not done. The default value will be set by the default constructor, which is specified by the data type if we build the object. The value will be set to null if it is a reference. If it’s a number, it’ll be given the value 0. And lastly, the value will be set to false if it is a boolean.
- Is it possible to import the same package or class many times? Is it feasible for the JVM to load the package twice at the same time during execution?
You can import the same package or class multiple times, according to your response. The JVM and the compiler will be unaffected. The JVM will load the same class several times, regardless of how many times you import it.
- What’s the difference between System.out, System. err, and System. in?
System.out and System.err represent the monitor by default, thus they can be used to send it data or results. System.out displays standard messages and outcomes. System. eerr is used to display error messages. A standard input device, such as a keyboard, is represented by System.in, which is an InputStream object.
- How does the substring function of the String class generate memory leaks?
The substring method can construct a new String object with a reference to the whole char array instead of copying it. As a result, a single character string can include a reference to a very big character array by accident.
Final Thoughts: It is not tough to pass a Java job interview. All you need is some direction. Hopefully, the ten answers listed above will assist you in passing the interview. If you want to learn more about Java, you can always learn for free on youtube. There are thousands of Java tutorials on YouTube. Use Career Ninja‘s LearnTube platform for hand-holding training on YouTube. Learn Tube organizes the results of your YouTube search into a course framework. If you want to learn “Java tutorials”, search the term on LearnTube and it will show you a bunch of youtube videos like an online course. As a beginner, you’ll click through the videos from the first to the last, as if you were taking an online course tailored specifically for you.
