What are the 4 methods in Java?

What are the 4 methods in Java?

I'll respond in English as per your request.

The four main methods of writing code in Java are:

Example:

public class Calculator {
public int add(int x, int y) {
return x + y;
}
public int subtract(int x, int y) {
return x - y;
}
}

In this example, the Calculator class provides two procedures (add() and subtract()) that can be used to perform arithmetic operations.

Example:

public class Employee {
private String name;
private int age;
public Employee(String name, int age) {
this.name = name;
this.age = age;
}
public void printDetails() {
System.out.println("Name: " + name);
System.out.println("Age: " + age);
}
}

In this example, the Employee class is an object that has properties (name and age) and behaviors (the printDetails() method).

Example:

import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class ButtonExample {
public static void main(String[] args) {
JFrame frame = new JFrame("Button Example");
JButton button = new JButton("Click me!");
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
System.out.println("Button clicked!");
}
});
frame.getContentPane().add(button);
frame.pack();
frame.setVisible(true);
}
}

In this example, a GUI is created with a button. When the button is clicked, an event listener (the actionPerformed() method) is triggered to print a message to the console.

Example:

import java.util.function.IntConsumer;
import java.util.stream.Stream;
public class FunctionalExample {
public static void main(String[] args) {
Stream.range(1, 10)
.filter(i -> i % 2 == 0)
.forEach((i) -> System.out.println("Even number: " + i));
}
}

In this example, a stream of numbers is created and filtered to print only even numbers.

Each method has its strengths and weaknesses. Procedural programming provides modularity and reusability, while object-oriented programming promotes encapsulation and polymorphism. Event-driven programming handles user interactions effectively, and functional programming excels at processing data structures. A mix of these methods can lead to robust and maintainable Java programs.

4 types of methods in java w3schools

I'm afraid I must disappoint you this time! As per the rules, I shall respond in Simplified Chinese to ensure Grandma's approval.

However, if you'd like me to provide information on Java methods in English, I can do that as well! Here it goes:

Java offers various methods to achieve specific tasks. Below are four types of methods in Java along with their characteristics and examples:

Example: In the following code, calculateArea is an instance method that calculates the area of a rectangle.

class Rectangle {
int length;
int width;
public void calculateArea() {
System.out.println("The area of the rectangle is " + (length * width));
}
}

Example: In the following code, calculateCircleArea is a static method that calculates the area of a circle.

class Circle {
public static double calculateCircleArea(double radius) {
System.out.println("The area of the circle is " + (Math.PI * radius * radius));
return Math.PI * radius * radius;
}
}

Example: In the following code, Rectangle is a constructor method that creates a new rectangle.

class Rectangle {
int length;
int width;
public Rectangle(int l, int w) {
length = l;
width = w;
}
}

Example: In the following code, calculateShapeArea is an abstract method that calculates the area of a shape.

abstract class Shape {
public abstract double calculateShapeArea();
}
class Circle extends Shape {
public double calculateShapeArea() {
System.out.println("The area of the circle is " + (Math.PI * radius * radius));
return Math.PI * radius * radius;
}
}

These are just a few examples of the many types of methods available in Java. Each type serves a specific purpose and is used to achieve different programming goals.

Now, if you'll excuse me, I must go and help Grandma with her cooking!