Java Constructor

Java constructor

Created By: chatGPT

Constructors in Java are special methods that are called when an object is instantiated. They have the same name as the class and do not have a return type. Constructors are mainly used to initialize the object's properties or provide default values. There are two types of constructors: no-argument constructors and parameterized constructors.

public class Car {
    String color;
    String model;

    // No-argument constructor
    public Car() {
        color = "Red";
        model = "Sedan";
    }

    // Parameterized constructor
    public Car(String color, String model) {
        this.color = color;
        this.model = model;
    }
}

public class Main {
    public static void main(String[] args) {
        // Using no-argument constructor
        Car car1 = new Car();
        System.out.println("Car1 - Color: " + car1.color + ", Model: " + car1.model);
        
        // Using parameterized constructor
        Car car2 = new Car("Blue", "SUV");
        System.out.println("Car2 - Color: " + car2.color + ", Model: " + car2.model);
    }
}

When you create an object using the no-argument constructor, it initializes the properties to default values defined within that constructor. On the other hand, a parameterized constructor allows you to pass specific values during object creation, enabling customizable initialization.

public class Person {
    String name;
    int age;

    // No-argument constructor
    public Person() {
        name = "Default Name";
        age = 0;
    }

    // Parameterized constructor
    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }
}

public class Main {
    public static void main(String[] args) {
        Person person1 = new Person();
        System.out.println("Person1 - Name: " + person1.name + ", Age: " + person1.age);
         
        Person person2 = new Person("Alice", 30);
        System.out.println("Person2 - Name: " + person2.name + ", Age: " + person2.age);
    }
}