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

Alternatively, you can create a counter with an initializer block and a static variable.

class SomeClass
{
    private static int instanceCounter;
    {
         instanceCounter++;
    }
}

Initializer blocks get copied by the compiler into every constructor, so, you will have to write it once no matter how many constructors you will need (As referred into the above link). The block in {} runs every time you create a new object of the class and increases the variable counter by one. And of course get the counter by something like:

public static int getInstanceCounter()
{
    return instanceCounter;
}

or directly

int numOfInstances = SomeClass.instanceCounter;

If you do not make numOfInstances private