Java Interview Questions (Part-3) | Read Now

Java Interview Questions (Part-3) will contain some more content of the core questions asked by the interviewers in internships or jobs that can help you pass your test.

41] How Java computer language differs from C++?

• Java and C++, both are platform independent.
• Java restricts the usage of “goto” statements, whereas C++ supports it.
• Java restricts the usage of multiple inheritance in its code, whereas C++ does the opposite.
• Java utilizes both the compiler with interpreter, whereas C++ utilizes just the compiler.
• Structures plus unions are never supported by Java, but C++ do supports them.
• Java is not hardware-friendly, whereas C++ is.
• Operator namely “Right shift” can be utilized by Java but not with C++.
• Java and C++, both are OOP languages.
• Overloading of operators is never supported by Java, but C++ do support it.

42] What type of memory sectors by JVM are being assigned?

1. Stack sector: Stack sector in Java stores the various frames which contains partial outcomes and also variables that are local.
2. Method sector: Method sector in Java contains the per-class frameworks including code, pool, etc.
3. Native functional stack sector: All the native methodologies are being stored in this specific sector.

43] Can you define the “Class loader” in Java computer language?

“Class loader” is one type of a sub-system that is found under JVM. It’s central aim is to load the class files stored. In total, there are 3 sorts of class loader and they are as mentioned:

1. Boot-strap: This is the topmost classloader.
2. Extension: This is the child node of the boot-strap classloader.
3. Application: This is the child node of the extension classloader. It is also abbreviated as classloader System.

44] What if I write “static public void” instead of “public static void”?

Yes, you can write that and the code implements correctly. The central reason behind is the sequence of writing the same does not matter.

45] Can one utilize this() or super() both in any constructors?

No, the central reason behind is, both of them should be the first statement in the whole script.

46] If one wishes to construct a copy of any object, then what should the procedure called?

The procedure in which we can perfectly replicate any object is known as “Cloning of an object”. An interface namely java.lang.cloneable should be implemented.

47] Are you able to overload the main() methodology?

Yes, I can overload as many main() methodologies utilizing overloading strategy.

48] How the unchecked and checked exceptions differ?

Checked exceptions are all classes that extend class Throwable except RuntimeException and Failure, such as IOException, SQLException, and so on. Exceptions that are checked are evaluated at compilation time.

Unchecked exceptions are all classes that extend RuntimeException, such as ArithmeticException, NullPointerException, and so on. At compilation time, unchecked occurrences are not evaluated.

49] What does the block “finally” mean?

The “finally” block is the block of script that is capable to handle every error. Or, we can say, finally block is implemented every time and thus resolves the complex exception in the whole script.

50] What is the central reason behind object immutability?

The objects constructed in Java computer language are immutable as it utilizes the concept of string literals.

51] Give an illustration of immutable class in Java computer language.

public final class Student{  
final String idNumber;  
  
public Student(String idNumber){  
this.idNumber=idNumber;  
}  
  
public String getidNumber(){  
return idNumber;  
}  
  
}  

52] Why individuals utilize charArray() over Strings to store the sensitive data such as passwords?

String has its own string pool that stores the data for a lengthy period. Thus, through various strategies, anyone can extract the sensitive data such as passwords. Whereas, in case of charArray(), the last procedure is all set to blank or null whenever the tasks with sensitive data are accomplished. Thus, the sensitive info can not be easily extracted through charArray().

53] Point out the demerits of utilizing inner classes in Java computer language.

Inner classes significantly increase number of classes used by the programmer, which doubles the strain of the JVM because it must execute more operational functions for all those more classes, resulting in slower throughput.

Inner classes receive less assistance from IDEs than top tiers, which irritates programmers while dealing with them.

54] How an individual can relate the inner and nested class?

An Inner class is a sub-part of a nested class. In this way, they both can be linked.

55] How do you elaborate “garbage collection” in Java computer language?

Garbage storage is the procedure of retrieving runtime entities that are no longer in usage. It is implemented in order to optimize memory. To put it another way, it is the mechanism of deleting extraneous entities from storage to make more space and making it accessible for the JVM.  Java delivers 0 to the variables whose values are never set, as per garbage collection norms.

56] Which amongst final, finalize, and finally is the block, keyword, and methodology?

With respect to all three, finalize is the methodology, final is the keyword, and finally is a script block.

57] Point out the central aim of class “Runtime”.

To communicate with a Java execution environment, employ the Java Runtime class. The class Java Runtime contains methodologies for running a task, initiating the garbage collector, determining overall and spare memory, and so on.

58] Can you reference an unreferenced entity?

Yes, an unreferenced entity can be again referenced.

59] What is the description of “filter streams”?

Filter streams in Java computer language are the classes that are utilized to add some more features to all different streams.

60] How can we directly access the static class members?

You can utilize static import for the same task.