Why is Java Architectural Neutral?

Java uses Just-In-Time compiler to enable high performance. Just-In-Time compiler is a program that turns Java bytecode, which is a program that contains instructions that must be interpreted into instructions that can be sent directly to the processor.

Java provides several features that enable high performance, including:

1. Just-In-Time (JIT) compilation - Java uses a JIT compiler to improve the performance of the code at runtime. The JIT compiler compiles the bytecode to native machine code, optimizing it for the specific hardware and operating system on which it is running. This approach allows Java to achieve performance similar to that of native code while still maintaining the benefits of platform independence.

2. Garbage collection - Java's automatic garbage collection feature allows it to manage memory usage efficiently. This means that Java programs can avoid common memory-related errors such as memory leaks, resulting in more stable and reliable performance.

3. Multithreading support - Java provides built-in support for multithreading, allowing programs to run multiple threads of execution simultaneously. This feature enables Java programs to take advantage of modern multi-core CPUs, improving performance on multi-threaded applications.

4. Platform independence - Java's platform independence allows it to run on a variety of hardware and operating systems. This means that Java programs can be optimized for the specific hardware and operating system on which they are running, leading to better performance.

5. Bytecode format - Java's bytecode format is highly optimized, allowing for efficient execution and minimizing the overhead of interpretation. This approach allows Java to achieve good performance even on systems with limited resources.

Overall, Java's combination of JIT compilation, garbage collection, multithreading support, platform independence, and optimized bytecode format enables it to deliver high performance, making it a popular choice for building high-performance applications.

Java is considered a dynamic language for several reasons:

1. Late binding - Java uses late binding, also known as dynamic binding, which means that the determination of which method to call happens at runtime, rather than at compile time. This allows for more flexibility and adaptability in program execution, as the method to be called can be determined based on the state of the program at runtime.

2. Reflection - Java has a built-in reflection API that allows the program to examine and modify itself at runtime. This feature enables dynamic loading of classes, invocation of methods by name, and inspection of class metadata at runtime.

3. Dynamic class loading - Java allows classes to be loaded at runtime, rather than at compile time. This feature enables the program to dynamically load and unload classes based on runtime conditions, providing greater flexibility in program execution.

4. Dynamic memory allocation - Java uses dynamic memory allocation, allowing the program to allocate and deallocate memory at runtime as needed. This feature enables more efficient memory management and better resource utilization.

5. Dynamic code execution - Java provides a built-in scripting engine, allowing for the execution of dynamic code at runtime. This feature enables the program to execute code that is generated or modified during runtime, providing greater flexibility in program execution.

In summary, Java is considered a dynamic language due to its support for late binding, reflection, dynamic class loading, dynamic memory allocation, and dynamic code execution. These features enable Java programs to be more flexible, adaptable, and efficient, making it a popular choice for building dynamic, high-performance applications.

Java - Inheritance
Java - Overriding
Java - Polymorphism
Java - Abstraction
Java - Encapsulation
Java - Interfaces
Java - Packages
Java Advanced
Java - Data Structures
Java - Collections
Java - Generics
Java - Serialization
Java - Networking
Java - Sending Email
Java - Multithreading
Java - Applet Basics
Java - Documentation
Java Useful Resources
Java - Questions and Answers
Java - Quick Guide
Java - Useful Resources
Java - Discussion
Java - Examples
Selected Reading
Developer's Best Practices
Questions and Answers
Effective Resume Writing
HR Interview Questions
Computer Glossary
Who is Who
Java Interview Questions
Advertisements
Previous Page Next Page
Dear readers, these Java Interview Questions have been designed especially to get you acquainted with the nature of questions you may encounter during your interview for the subject of Java Programming Language. As per my experience, good interviewers hardly planned to ask any particular question during your interview, normally questions start with some basic concept of the subject and later they continue based on further discussion and what you answer ?

What do you know about Java?
Java is a high-level programming language originally developed by Sun Microsystems and released in 1995. Java runs on a variety of platforms, such as Windows, Mac OS, and the various versions of UNIX.

What are the supported platforms by Java Programming Language?
Java runs on a variety of platforms, such as Windows, Mac OS, and the various versions of UNIX/Linux like HP-Unix, Sun Solaris, Redhat Linux, Ubuntu, CentOS, etc.

List any five features of Java?
Some features include Object Oriented, Platform Independent, Robust, Interpreted, Multi-threaded

Why is Java Architectural Neutral?
It’s compiler generates an architecture-neutral object file format, which makes the compiled code to be executable on many processors, with the presence of Java runtime system.

How Java enabled High Performance?
Java uses Just-In-Time compiler to enable high performance. Just-In-Time compiler is a program that turns Java bytecode, which is a program that contains instructions that must be interpreted into instructions that can be sent directly to the processor.

Why Java is considered dynamic?
It is designed to adapt to an evolving environment. Java programs can carry extensive amount of run-time information that can be used to verify and resolve accesses to objects on run-time.

Variables defined inside methods, constructors or blocks are called local variables. The variable will be declared and initialized within the method and it will be destroyed when the method has completed.

In Java, a local variable is a variable that is defined within a method, constructor, or a block of code. It is only accessible within the block of code in which it is declared and cannot be accessed from outside that block. Local variables are created on the stack and their memory is automatically freed when the method, constructor, or block of code execution is completed.

Local variables have a scope that is limited to the method, constructor, or block of code in which they are declared. This means that they are only accessible within the block in which they are declared and cannot be accessed from outside that block. The lifetime of a local variable starts when the method, constructor, or block of code is entered and ends when it is exited.

Here is an example of a local variable in Java:

public void doSomething() {
   int i = 10;
   // Use the local variable i here.
}

In the example above, the local variable i is declared within the doSomething method and is only accessible within that method.

Instance variables are variables within a class but outside any method. These variables are instantiated when the class is loaded.

In Java, an instance variable is a variable that is declared within a class but outside of any method, constructor, or block of code. Unlike local variables, instance variables are associated with an instance of an object and are created when an object of the class is instantiated. This means that each object of the class will have its own copy of the instance variables, and changes to an instance variable in one object will not affect the value of the same instance variable in another object.

Instance variables have a default value, which is either null for reference types or 0 for numeric types. However, the default value can be overridden by assigning a value to the instance variable in the constructor or by using a setter method.

Instance variables are declared using the private access modifier to ensure that they cannot be accessed directly from outside the class. Instead, they are accessed using getter and setter methods.

Here is an example of an instance variable in Java:

public class Student {
   private int studentId;
   private String studentName;

   // Getter and setter methods for the instance variables
   public int getStudentId() {
      return studentId;
   }

   public void setStudentId(int studentId) {
      this.studentId = studentId;
   }

   public String getStudentName() {
      return studentName;
   }

   public void setStudentName(String studentName) {
      this.studentName = studentName;
   }
}

In the example above, the class Student has two instance variables studentId and studentName. Each object of the Student class will have its own copy of these instance variables, and their values can be accessed and modified using the getter and setter methods.