Constructor in Java 20

In Java, a constructor is a special method that is used to initialize an object of a class. When an object is created using the new keyword, the constructor is called to initialize the object.

Here's an example of a constructor for a Car class:

public class Car {
    String make;
    String model;
    int year;
public Car(String make, String model, int year) {

        this.make = make;

        this.model = model;

        this.year = year;

    }

}

In this example, the Car class has three instance variables: make, model, and year. The constructor takes three parameters to initialize these variables.

To create a new Car object using the constructor, you would use the following code:

Car myCar = new Car("Toyota", "Camry", 2021);

This creates a new Car object with the make "Toyota", model "Camry", and year 2021.

Here's another example of a constructor for a Student class:

public class Student {
    String name;
    int age;
    String major;
public Student(String name, int age, String major) {

        this.name = name;

        this.age = age;

        this.major = major;

    }
public void displayInfo() {

        System.out.println("Name: " + name);

        System.out.println("Age: " + age);

        System.out.println("Major: " + major);

    }

}

In this example, the Student class has three instance variables: name, age, and major. The constructor takes three parameters to initialize these variables.

The Student class also has a method called displayInfo() that prints out the values of the instance variables.

To create a new Student object using the constructor and call the displayInfo() method, you would use the following code:

Student myStudent = new Student("John", 20, "Computer Science");
myStudent.displayInfo();

This creates a new Student object with the name "John", age 20, and major "Computer Science", and then calls the displayInfo() method to print out the values of the instance variables.