CODEWITHSUNDEEP
java
Stepan
Stepan

Reputation: 1431

Java instance variables

I am learning Java using Codecademy. I am trying to write code that would make an object (in this case a 3 year old dog named Spike) to run on on n legs where n = age. I tried "brute force debugging", but that didn't work. How should I change the line "how to change this" to make the code work?

class Dog {
    public Dog(int dogsAge) {
        int age = dogsAge;
    }

    public void bark() {
        System.out.println("Woof!");
    }

    public void run(int feet) {
        System.out.println("Your dog ran " + feet + " feet!");
    }

    public static void main(String[] args) {
        Dog spike = new Dog(3);
        spike.bark();
        spike.run(this.age); // How to change this?
    }
}

Upvotes: 0

Views: 258

Answers (3)

Vikrant Kashyap
Vikrant Kashyap

Reputation: 6876

class Dog {
int age;   //your mistake
 public Dog(int dogsAge){
 this.age = dogsAge;
 }
 public void bark() {
    System.out.println("Woof!");
}

public void run(int feet) {
    System.out.println("Your dog ran " + feet + " feet!");
}

public static void main(String[] args) {
    Dog spike = new Dog(3);
    spike.bark();
    spike.run(spike.age); // How to change this?
}

Upvotes: 2

Chunko
Chunko

Reputation: 352

Your class needs to - add storage for the age variable - set that value in the construcor - provide a way for your main function to access it

class Dog {
 private int age; //storage for the age value within the instance
 public Dog(int dogsAge){
   this.age = dogsAge; // set the value
 }
 // provide a way to access the age
 public int getAge() {
   return this.age;
 }
 public void bark(){
   System.out.println("Woof!");

 }
 public void run(int feet) {
   System.out.println("Your dog ran " + feet + " feet!");
 }


 public static void main(String[] args) {
  Dog spike = new Dog(3);
  spike.bark();
  spike.run(spike.getAge()); // retrieve the age and use it
 }

}

Upvotes: 3

Abdelhak
Abdelhak

Reputation: 8387

Try to create a variable int age and initialize it in constructor like this:

  class Dog {
  int age;
 public Dog(int dogsAge){
    this.age = dogsAge;
  }

Upvotes: 2

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