Question

in java,

write code that defines a class named Cat The class should have breed, name and weight as attributes.

include setters and getters for the methods for each attribute.

include a toString method that prints out the object created from the class, and a welcome message.

And use a constructor that takes in all the attributes to create an object.

Answer 1

Kindly note that toString() method is defined in Object Class in Java and since any Class in Java is actually an Object of the Object Class , hence all classes already have a defined toString() method. If you simply print a Object (System.out.println(obj)). This invokes the toString() method and a output is returned. Originally , this output is the hashcode of the current object. Hence , we need to override the toString() method to print information as per our requirement.

Here is the complete implementation

class Cat{
    /* Attributes are private to provide more abstraction and therefore other classes need to use getter and setter functions to access these attributes */
    private String  breed;
    private String  name;
    private double weight;
    
    /* Class Constructor for initialisation of attributes */
    public Cat(String breed , String name , double weight){
        this.breed = breed;
        this.name = name;
        this.weight = weight;
    }
    
    /* Setter Functions */
    public void setBreed(String breed){
        this.breed = breed;
    }
    public void setName(String name){
        this.name = name;
    }
    public void setWeight(double weight){
        this.weight = weight;
    }
    
    /* Getter Functions */
    public String getBreed(){
        return breed;
    }
    public String getName(){
        return name;
    }
    public double getWeight(){
        return weight;
    }
    
    /* Overriding toString function as it is already defined in the Object Class
       and if you call toString() without overriding it in your class , the output 
       will be the hashCode of the Object Eg:- Cat@453290 where last 6 digits are 
       hashcode of the object. Hence , we need to override the method*/ 
    @Override
    public String toString(){
         return ("Breed is : "+breed+",  Name is : "+name+
         ",  Weight is : "+weight+ "---WELCOME CAT---");
    }
    
} 
public class HelloWorld{

     public static void main(String []args){
         /* Creating two different objects */
        Cat C1=new Cat("Persian","Bella",6);  
        Cat C2=new Cat("Maine Coon","Lucy",9);
        /* Calling their toString method , which can be done by simple printing 
           the object in Java*/
        System.out.println(C1);
        System.out.println(C2); 
     }
}

Here is the screenshot of the output.