Creating a Java Dog Class with Parameterized Constructor

Last update on December 21 2024 09:37:15 (UTC/GMT +8 hours)

Parameterized Constructor:
Write a Java program to create a class called Dog with instance variables name and color. Implement a parameterized constructor that takes name and color as parameters and initializes the instance variables. Print the values of the variables.

Sample Solution:

Java Code:

Dog.java

// Define the Dog class
public class Dog {
    // Private instance variables
    private String name;
    private String color;

    // Parameterized constructor
    public Dog(String name, String color) {
        // Initialize name with the provided parameter
        this.name = name;
        // Initialize color with the provided parameter
        this.color = color;
    }

    // Main method to test the Dog class
    public static void main(String[] args) {
        // Create a new Dog object using the parameterized constructor
        Dog myDog = new Dog("Bailey", "Black");
        // Print the values of the instance variables
        System.out.println("Dog's Name: " + myDog.name);
        System.out.println("Dog's Color: " + myDog.color);
    }
}

Output:

Dog's Name: Bailey
Dog's Color: Black

Explanation:

• Define the Dog class:
• The Dog class is defined with the keyword class.
• Private instance variables:
• The Dog class has two private instance variables: name (a String) and color (a String).
• Parameterized constructor:
• The parameterized constructor Dog(String name, String color) is defined.
• Inside the constructor, this.name is initialized with the provided name parameter.
• this.color is initialized with the provided color parameter.
• Main method:
• The main method is defined to test the Dog class.
• A new Dog object (myDog) is created using the parameterized constructor, passing "Buddy" and "Brown" as arguments.
• The values of the instance variables (name and color) are printed to the console.

Note on Constructors:

In the above exercise, the parameterized constructor for the Dog class works by:

• Initialization with Parameters: When a new Dog object is created, the parameterized constructor is called with specific values for name and color.
• Setting Values: The constructor initializes the instance variables name and color with the provided values, ensuring that the object is created with specific attributes.
• Encapsulation: By keeping the instance variables private and initializing them through the constructor, the class ensures that the variables are set only when a new object is created, promoting controlled initialization and data integrity.

Java Code Editor:

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