Java
Java programming is object-oriented, class-based and platform-independent in nature, being one of the most popular programming languages today.
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In last 5 to 10 years use of internet has been increased massively. Internet is being used for commercial as well as non-commercial purpose also professional as well as non-professional purpose. Hence the amount of information that is being poured on internet is very large. Every piece of data may it be your personal data, professional data, finance data is easily available on internet. The rise of social media has also added to it. This has led to increase in Cyber attacks.
Cyber attacks has increased drastically in last decade. It is causing the largest damage to companies and as well as the individuals on personal level. Cyber attacks is one of the largest reasons of financial losses to companies hence in order to avoid that the companies now have more aware and became more responsible when it comes securing their assets over the internet. This has led to rise Cyber Security industry.
Cyber Security market is fastest growing market in the world at current stage. Hence there is large vacancy of skilled professionals in Cyber security and there this course comes in picture.
This course covers all areas that you should have knowledge if you want to enter in Cyber Security field. It will create a solid base for the Cyber security on the basis of which an individual can built his career and can have advanced learning
and training. This course is capable of providing the individual an entry level job in Cyber security industry conditionally the individual should perform well throughout
As a student we always look to learn things that can help us to a get job and it should last in future. If you talk about Cyber security is one of the largest growing industry in world. Don’t trust me go to Google and search you will find the answer. You search anything fastest growing industry , fastest growing technology, fastest growing career option in each list you will find Cyber security so the early you start your journey the more it will be fruitful to student. error, est. Ea, consequatur.
Java Course
- What is Java?
- History and Features of Java
- Hello Java Program
- Internal How to set the path
- JDK, JRE, and JVM (Java Virtual Machine)
- Operators, Keywords, and
- Control Statements like if-else, switch, For loop, while loop, etc.
- Data types & type Casting
- Naming convention of Java
- Classes, Objects, and Features. It explains how to declare a class, how to create an object in Java.
- Object declaration and initialization
- Anonymous object in Java
- Class and Objects in Java with Realtime Examples
- Variables: Instance, Static, local
- Methods in Java
- Use of method in Java
- Method declaration, method signature
- Types of methods in Java: Instance method, static method
- Calling of method
- Java main method
- Return type in Java
- Method Overloading
– Method Overriding
- What is Static keyword?
- Static variable
- Static method
- Static block, Instance block
- Static Nested Class in Java
- Difference between static variable and instance variable, static method and instance method, static block, and instance block.
- Super keyword
- Calling of superclass instance variable
- Superclass constructor
- Superclass method.
- This keyword
- Calling of current class constructor, and method.
- Final keyword
- Final variable
- Final method
- Final class.
- What is Constructor in Java?
- Types of constructors: Default and Parameterized constructors
- Java constructor overloading
- What is Access modifier?
- Types of access modifiers like private, default, protected, and public
- Inheritance
- Encapsulation
- Polymorphism
- Abstraction
- How to declare package
- Package naming conventions
- Sub packages
- Types of packages such as user-defined packages, built-in packages
- What is Inner class in Java?, Properties of inner class, Instantiating inner class.
- Types of inner class in Java
- FileOutputStream, FileInputStream
- ByteArrayOutputStream, ByteArrayInputStream
- DataOutputStream, DataInputStream
- Java ObjectStream, Java ObjectStreamField
- FileWriter, FileReader
- OutputStreamWriter, InputStreamReader
- What is Collections Framework?
- Hierarchy of Collection Framework
- List
- Set
- Queue
- Deque
- Map
- Exception Handling in Java
- Try-catch block
- Multiple Catch Block
- Nested try block
- Finally block
- Throw Keyword
- Throws Keyword
- Java multithreading
- Thread scheduler
- Calling run() method
- Joining a thread
- Naming a thread
- Thread priority,
- Thread group
- JDBC Drivers
- Steps to connect to Database
- Connectivity with Oracle
- Connectivity with MySQL
- Types of JDBC statements: Statement, Prepared statement, Callable statement
What our Students say
FAQ'S
Among the various programming languages available in the market, Python has made its way to become one of the fastest-growing languages.
Java Interview Questions for Freshers
- Why is Java a platform independent language?
- Why is Java not a pure object oriented language?
- Difference between Heap and Stack Memory in java. And how java utilizes this.
- Can java be said to be the complete object-oriented programming language?
- How is Java different from C++?
- Pointers are used in C/ C++. Why does Java not make use of pointers?
- What do you understand by an instance variable and a local variable?
- What are the default values assigned to variables and instances in java?
- What do you mean by data encapsulation?
- Tell us something about JIT compiler.
1. Why is Java a platform independent language?
Java language was developed in such a way that it does not depend on any hardware or software due to the fact that the compiler compiles the code and then converts it to platform-independent byte code which can be run on multiple systems.
- The only condition to run that byte code is for the machine to have a runtime environment (JRE) installed in it
2. Why is Java not a pure object oriented language?
Java supports primitive data types – byte, boolean, char, short, int, float, long, and double and hence it is not a pure object oriented language.
3. Difference between Heap and Stack Memory in java. And how java utilizes this.
Stack memory is the portion of memory that was assigned to every individual program. And it was fixed. On the other hand, Heap memory is the portion that was not allocated to the java program but it will be available for use by the java program when it is required, mostly during the runtime of the program.
Java Utilizes this memory as –
- When we write a java program then all the variables, methods, etc are stored in the stack memory.
- And when we create any object in the java program then that object was created in the heap memory. And it was referenced from the stack memory.
Example- Consider the below java program:
class Main {
public void printArray(int[] array){
for(int i : array)
System.out.println(i);
}
public static void main(String args[]) {
int[] array = new int[10];
printArray(array);
}
}For this java program. The stack and heap memory occupied by java is –
Main and Print Array is the method that will be available in the stack area and as well as the variables declared that will also be in the stack area.
And the Object (Integer Array of size 10) we have created, will be available in the Heap area because that space will be allocated to the program during runtime.
4. Can java be said to be the complete object-oriented programming language?
It is not wrong if we claim that java is the complete object-oriented programming language. Because Everything in Java is under the classes. And we can access that by creating the objects.
But also if we say that java is not a completely object-oriented programming language because it has the support of primitive data types like int, float, char, boolean, double, etc.
Now for the question: Is java a completely object-oriented programming language? We can say that – Java is not a pure object-oriented programming language, because it has direct access to primitive data types. And these primitive data types don’t directly belong to the Integer classes.
5. How is Java different from C++?
- C++ is only a compiled language, whereas Java is compiled as well as an interpreted language.
- Java programs are machine-independent whereas a c++ program can run only in the machine in which it is compiled.
- C++ allows users to use pointers in the program. Whereas java doesn’t allow it. Java internally uses pointers.
- C++ supports the concept of Multiple inheritances whereas Java doesn’t support this. And it is due to avoiding the complexity of name ambiguity that causes the diamond problem.
6. Pointers are used in C/ C++. Why does Java not make use of pointers?
Pointers are quite complicated and unsafe to use by beginner programmers. Java focuses on code simplicity, and the usage of pointers can make it challenging. Pointer utilization can also cause potential errors. Moreover, security is also compromised if pointers are used because the users can directly access memory with the help of pointers.
Thus, a certain level of abstraction is furnished by not including pointers in Java. Moreover, the usage of pointers can make the procedure of garbage collection quite slow and erroneous. Java makes use of references as these cannot be manipulated, unlike pointers.
7. What do you understand by an instance variable and a local variable?
Instance variables are those variables that are accessible by all the methods in the class. They are declared outside the methods and inside the class. These variables describe the properties of an object and remain bound to it at any cost.
All the objects of the class will have their copy of the variables for utilization. If any modification is done on these variables, then only that instance will be impacted by it, and all other class instances continue to remain unaffected.
Example:
class Athlete {
public String athleteName;
public double athleteSpeed;
public int athleteAge;
}Local variables are those variables present within a block, function, or constructor and can be accessed only inside them. The utilization of the variable is restricted to the block scope. Whenever a local variable is declared inside a method, the other class methods don’t have any knowledge about the local variable.
Example:
public void athlete() {
String athleteName;
double athleteSpeed;
int athleteAge;
}
8. What are the default values assigned to variables and instances in java?
- There are no default values assigned to the variables in java. We need to initialize the value before using it. Otherwise, it will throw a compilation error of (Variable might not be initialized).
- But for instance, if we create the object, then the default value will be initialized by the default constructor depending on the data type.
- If it is a reference, then it will be assigned to null.
- If it is numeric, then it will assign to 0.
- If it is a boolean, then it will be assigned to false. Etc.
9. What do you mean by data encapsulation?
- Data Encapsulation is an Object-Oriented Programming concept of hiding the data attributes and their behaviours in a single unit.
- It helps developers to follow modularity while developing software by ensuring that each object is independent of other objects by having its own methods, attributes, and functionalities.
- It is used for the security of the private properties of an object and hence serves the purpose of data hiding.
10. Tell us something about JIT compiler.
- JIT stands for Just-In-Time and it is used for improving the performance during run time. It does the task of compiling parts of byte code having similar functionality at the same time thereby reducing the amount of compilation time for the code to run.
- The compiler is nothing but a translator of source code to machine-executable code. But what is special about the JIT compiler? Let us see how it works:
- First, the Java source code (.java) conversion to byte code (.class) occurs with the help of the javac compiler.
- Then, the .class files are loaded at run time by JVM and with the help of an interpreter, these are converted to machine understandable code.
- JIT compiler is a part of JVM. When the JIT compiler is enabled, the JVM analyzes the method calls in the .class files and compiles them to get more efficient and native code. It also ensures that the prioritized method calls are optimized.
- Once the above step is done, the JVM executes the optimized code directly instead of interpreting the code again. This increases the performance and speed of the execution.
