java Objects

[akhilchandranms]

How many object can be created for a class in java

[JamesCherrill]

In practice it's limited by the available memory, but if each instance does not have big data members you can create tens of millions of instances

[jwenting]

technically, only 1 class instance is created for any class per classloader.
After that, any number of instance of that class can also be created, as needed, discarded, reused, serialised, deserialised, etc. etc.

[JamesCherrill]

Just for fun I created a small class (one int as its members)

class X{
   int i=0;
}

and an array to keep them in

X[] instances = new X[100_000_000];

then looped creating instances until it ran out of memory

for (int i = 0; i < instances.length; i++) {
    instances[i] = new X();
    if (i % 1_000_000 == 0) {
        System.out.println(i / 1_000_000 + " million");
    }
}

Using NetBeans with its default memory settings (2 Gig on my 8 Gig machine)it ran for 1 1/2 minutes before crashing with an out of memory exception, having created and kept over 54 million instances.