How to Count Number of Instances of a Class

Question

Can anyone tell me how to count the number of instances of a class?

Here\'s my code

public class Bicycle {

    //instance variables
    public int          


        

Answer 1

public class Number_Objects {

    static int count=0;
    Number_Objects(){
        count++;
    }

    public static void main(String[] args) {

        Number_Objects ob1=new Number_Objects();
        Number_Objects ob2=new Number_Objects();
        Number_Objects obj3=new Number_Objects();
        System.out.print("Number of objects created :"+count);
    }

}

Answer 2

If you want to count and test instances based on the number of objects created, you can use a loop to see what really is happening. Create a constructor and use a static counter

public class CountInstances {
public static int count;
public CountInstances() {
    count++;
}
public int getInstaces() {
    return count;
}
public static void main(String []args) {
    for(int i= 0; i<10; i++) {  
        new CountInstances();
    }       
    System.out.println(CountInstances.count);
  } 
}

Answer 3

why not using a static counter?

public class Bicycle {

    private static int instanceCounter = 0;

    //instance variables
    public int gear, speed, seatHeight;
    public String color;

    //constructor
    public Bicycle(int gear, int speed, int seatHeight, String color) {
        gear = 0;
        speed = 0;
        seatHeight = 0;
        color ="Unknown";      
instanceCounter++;
    }

    public int countInstances(){
        return instanceCounter;
    }

........