Java

Question 1

What is Object Oriented Programming (OOPs)?

Answer 1

Is a way of organizing the code by using object-oriented principles. It models real world entities as objects which encapsulate data and behavior. Is objects talking to each other.

Question 2

method

Answer 2

Is a building block of a object oriented program. Blueprint of definining the behavior of an object. Like what a character is able to do in a video game.

Question 3

What is a class ?

Answer 3

Is a building block of a object oriented program. Blueprint of objects having common properties. Like a blue print of a character

Question 4

Object

Answer 4

is an instance of a class. Is what the class is building – in a video game is basically a character

Question 5

Method

Answer 5

Is a building block of a object oriented program. Blueprint of definining the behavior of an object. Like what a character is able to do in a video game.

Question 6

Interface

Answer 6

It serves as a blueprint for classes. s a contract that defines a set of methods or properties that a class must implement. That cannot be instated.

// Interface declaration
interface Animal {
// Method signature
void makeSound();

// Constant
String TYPE = "Animal"; }

// Class implementing the interface
class Dog implements Animal {
// Implementing the method from the interface
public void makeSound() {
System.out.println(“Dog barks”);
}
}

public class Main {
public static void main(String[] args) {
Dog dog = new Dog();
dog.makeSound(); // Output: Dog barks
System.out.println(Animal.TYPE); // Output: Animal
}
}

Question 7

abstraction

Answer 7

is a a blueprint for classes that cannot be instantiated directly

Question 8

Encapsulation

Answer 8

is the bundling of data that operates into a single unit called a class. It includes
1. Data Hiding
2.Public interface
3. Data validation

// Class definition
public class Car {
// Fields
private String model;
private int year;

// Getter for model
public String getModel() {
    return model;
}

// Setter for model
public void setModel(String model) {
    this.model = model;
}

// Getter for year
public int getYear() {
    return year;
}

// Setter for year
public void setYear(int year) {
    this.year = year;
} }

Question 9

Polymorphism

Answer 9

It means that different objects can use the same method or function name, but each one can act in its unique way.
1. Method overriding-it occurs when a class has multiple methods with the same name but different parameters.
class Animal {
public void makeSound() {
System.out.println(“Animal makes a sound”);
}
}

class Dog extends Animal {
@Override
public void makeSound() {
System.out.println(“Dog barks”);
}
}

public class Main {
public static void main(String[] args) {
Animal animal = new Dog(); // Polymorphism
animal.makeSound(); // Output: Dog barks
}
}

2. Method Overloading occurs when a class has multiple methods with the same name but different parameters
   class Calculator {
   public int add(int a, int b) {
   return a + b;
   }public double add(double a, double b) {
   return a + b;
   }
   }

public class Main {
public static void main(String[] args) {
Calculator calculator = new Calculator();
int sum1 = calculator.add(2, 3); // Invokes the int version of add()
double sum2 = calculator.add(2.5, 3.5); // Invokes the double version of add()
}
}

Question 10

Inheritance

Answer 10

It’s passing down traits from the parent class to child class.

Question 11

JDK

Answer 11

JAVA develoment kit it contains the compiler and debugger and JRE

Question 12

JRE

Answer 12

Java run time environment it contains the libraries and the JVM

Question 13

What is spring boot

Answer 13

Is an open source Java framework

Question 14

Overloading

Answer 14

it occurs when a class has multiple methods with the same name but different parameters.

Question 15

overriding

Answer 15

occurs when a class has multiple methods with the same name but different parameters

Question 16

What is association

Answer 16

relationship that has no ownership over another.

Question 17

What is a copy constructor ?

Answer 17

is a constructor that initializes an object through another object of the same class.